Hoofdstuk 2: The Chemistry of Living Things 2.1 All matter of consists of elements • Materie o Heeft massa o Bezet ruimte • Element o Fundamentele vorm dat niet afgberoken kan worden tot iets kleiner o Periodiek systeem der elementen • • •
Atoms, the smallest functional unit of any element, contain a nucleus and a cloud of electrons. The protons and neutrons in an atom’s nucleus account for most of its mass. Radioisotopes are unstable isotopes; an isotope has more or fewer neutrons than he usual number for that atom.
2.1.1 Atoms are the smallest functional units of an element • Behouden fysische en chemische eigenschappen • Celkern = nucleus o Protonen = positieve elementen o Neuronen = neutrale elementen Zelfde massa als protonen o Omsingeld door elektronen Schillen: • 1e 2 elektronen • 2e 8 elektronen • 3e 8 elektronen Zelfde aantal als protonen element is elektrisch neutraal Kleinere massa dan protonen & neutronen samen • PSE o Bovenaan: atoomnummer Aantal protonen o Onderaan: atoommassa Aantal neutronen & protonen 2.1.2 Isotopes have different number of neutrons • Isotopen hebben verschillende aantallen neutronen o Isotopen hebben ander aantal neutronen dan het normale element Zelfde atoomnummer, andere atoommassa Atoommassa in superscript bij element geplaatst • Vb. 14C o Vaak onstabiel radio-isotopen Geven energie af totdat ze stabielere toestand bereiken Door halveringstijd vorming van fossielen en stenen bepalen Recap: Atoms are made up of protons, neutrons and electrons. Radioisotopes are unstable atoms with an unusual number of neutrons that give off energy and particles as they decay to a more stable state.
2.2 Atoms combine to form molecules • Molecule = stabiele binding tussen 2 of meer (dezelfde) atomen • •
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Energy exists as either kinetic energy or potential energy. Three types of chemical binds account for the structures of molecules: covalent, ionic and hydrogen bonds. Covalent bonds are the strongest; hydrogen bonds are the weakest Over 99% of your body weight consists of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium and phosphorus.
2.2.1 Energy fuels life’s activities • Energie zorgt voor onze activiteiten o Energie = capaciteit om verandering in materie te veroorzaken o Potentiële energie = opgeslagen energie dat op dat moment niet gebruikt wordt Opgeslagen in bindingen die atomen in materie samenhouden Schil dichtst bij celkern potentiële energie laagst Beweging naar celkern: verliest energie Beweging van celkern weg: absorbeert energie o Kinetische energie = energie die gebruikt wordt Recap: stored energy is called potential energy, whereas energy doing work is called kinetic energy. Electrons in the energy level (or shell) closest to the nucleus have the least potential energy those in the outermost shell have the most potential energy.
2.2.2 Chemical bonds link atoms to form molecules • Chemische bindingen koppelen atomen om moleculen te vormen o Chemische binding = aantrekkingskracht tussen 2 atomen om stabiele structuur (buitenste rand gevuld) te verkrijgen 3 types • Covalente binding o Elektronenpaar wordt gedeeld o Sterkste binding o Enkelvoudige binding (1 elektronenpaar, vb. H²) o Dubbele binding (2 elektronenparen, vb. O²) o Atoom krijgt lading door elektronegatieviteit (hoogste elektronnegatieve waarde krijgt negatieve lading) • Ionische binding o Ion = geladen molecule / atoom o Tussen 2 tegengestelde geladen ionen o Elektrolyten = ionen in waterige oplossing Goede geleiders • Waterstofbinding o Zwakke binding o Tussen polaire molecules o Met H Recap: Strong covalent bonds from between atoms when they share pairs of electrons, ionic bonds from between oppositely charges ions, and weak hydrogen bonds occur between oppositely charged regions of polar molecules.
2.2.3 Living organisms contain only certain elements • Belangrijkste elementen in menselijke lichaam o Zuurstof (O) Deel van water en meeste organische moleculen o Koolstof (C) Ruggengraat alle organische moleculen o Waterstof (H) Deel van organische moleculen en water o Stikstof (N) Proteïnen en nucleïnezuur o Calcium (Ca) Botten zenuwen en spieren o Fosfor (P) Celmembraan en molecules om energie op te slaan (ATP), botten o Kalium (K) Zenuwen o Zwavelzuur Proteïnen o Natrium (Na) Lichaamsvocht, zenuwen o Chloor (Cl) Maagzuur, lichaamsvocht o Magnesium (Mg) Enzymen en spiercontractie o Ijzer (Fe) Hemoglobine (zuustofdrager in bloed) 2.3 Life depends on water • •
The polar nature of the water molecule accounts for its physical properties and for its unusually good qualities as a solvent for most other molecules and ions. Water is important in human temperature regulation.
2.3.1 Water is the biological solvent • Biologisch solvent o Andere dingen lossen er in op o Polaire vloeistof Hydrofiel Hydrofoob 2.3.2 Water helps regulate body temperature • Helpt lichaamstemperatuur op peil houden o Absorbeert warmte o Laat wartme vrij Zweten Recap: Most biological molecules dissolve readily in water because water is a polar molecule. The liquid nature of water facilitates the transport of biological molecules. Water absorbs and holds heat and can lower body temperature through evaporation.
2.4 The importance of hydrogen ions • • •
Molecules that can donate a hydrogen ion (H+) are called acids. Molecules that can accept H+ are called bases. The hydrogen ion concentration of a solution is expressed as PH. Buffers are pairs of molecules that tend to minimize changes in PH when an acid or base is added to a solution.
2.4.1 Acids donate hydrogen ions, bases accept them • Zuren leveren H+, basen accepteren ze o H2O OH- + H+ o Zure oplossing: concentratie H+ oplossing > concentratie H+ water o Basische oplossing: concentratie H+ oplossing < concentratie H+ water o Neutraliseren elkaar 2.4.2 The PH scale expresses hydrogen ion concentration • PH is een manier om concentratie H+ te meten o 0 14 7 = neutraal <7 = zuur >7 = base o Bloed = 7,4 o Lage concentratie H+ in lichaam Vervangen andere ionen waardoor moleculen niet goed meer functioneren Recap: Acids can donate hydrogen ions to a solution, whereas bases can accept hydrogen ions from a solution. The PH scale indicates the hydrogen ion concentration of a solution. The normal PH of blood is 7.4.
2.4.3 Buffers minimize changes in PH • PH-buffers o Buffer = een substantie die de veranderingen in PH minimaliseren o Biologische oplossingen: paar van zuur & base Als zuur wordt toegevoegd bufferende base zal teveel aan H+ opnemen Als base wordt toegevoegd bufferend zuur zal tekort aan H+ opvangen door H+ af te staan Recap: Buffers tend to minimize changes in PH in a solution. They help us maintain a stable PH in body fluids.
2.5 The organic molecules of living organisms • Organische moleculen o Koolstof (C) o Covalente bindingen • •
The backbone of all organic molecules as carbon. Organic molecules are formed by a process called dehydration synthesis (requiring energy) and broken down by a process called hydrolysis (releasing energy).
2.5.1 Carbon is the common building block of organic molecules • Koolstof is de gebruikelijke bouwsteen van organische molecule o Koolstof is zeldzaam in natuur o Structuur: 6 elektronen 1e schil: 2 (vol) 2e schil: 4 (4 ‘lege’ plaatsen) o 4 covalente bindingen aangaan Enkelvoudig: • Waterstof (H) • Stikstof (N) • Zuurstof (O) • Koolstof (C) Dubbel: • Zuurstof (O) • Koolstof (C) o Macromoleculen: geen limiet op lengte 2.5.2 Macromolecules are synthesized and broken down within the cell • Condensatiereactie (synthese) o Subunit toegevoegd waterstofmolecule afsplitsen o Vraagt energie • Hydrolyse o Covalente binding met subunit gebroken equivalent van waterstofatoom toevoegen o Geeft energie vrij • 4 klassen organische moleculen o Koolhydraat o Lipiden (vetten) o Proteïnen (eiwitten) o Nucleïnezuren Recap: Carbon is a key element of organic molecules because of the multiple ways it van form strong covalent bonds with other molecules. Organic molecules are synthesized by dehydration synthesis, a process that requires energy, and broken down by hydrolysis, which liberates energy. The four classes of organic molecules are carbohydrates, lipids, proteins and nucleic acids.
2.6 Carbohydrates: Used for energy and structural support • Structuur khoolydraat: 2H + 1O • • • •
Monosaccharides, or simple sugars, are a source of quick energy for cells. Complex carbohydrates (polysaccharides) are formed by linking simple sugars (monosaccharides) together by dehydration synthesis. Carbohydrates are primarily energy-storage molecules. Plants use them for structural support as well. In animals the storage molecule is glycogen; in plants it is starch.
2.6.1 Monosaccharides are simple sugars • Monosacchariden = suiker o Structuur: CnH2nOn o 5- of 6- voudige koolstofring o 4 belangrijkste suikers Ribose • 5 koolstoffen • 1 zuurstofatoom meer dan desoxyribose Desoxyribose • 5 koolstoffen • 1 zuurstofatoom minder dan ribose Fructose • 5 koolstoffen Glucose • 6 koolstoffen • Energie voor cellen 2.6.2 Oligisaccharides: More than one monosaccharide linked together • Oligosacchariden o Korte keten monosacchariden o Condensatiereactie o Voorbeelden Sucrose glucose + fructose Maltose glucose + glucose o Glycoproteïnen = covalent gebonden oligosacchariden Aangrenzende cellen verbinden Cel-cel herkenning en communicatie 2.6.3 Polysaccharides store energy • Polysacchariden slaan energie op o Lange keten monosachariden o Vertakt of niet-vertakt o Condensatiereactie o Dieren: glycogen o Planten: starch o Cellulose Planten: structureel transport Onverteerd: draagt bij tot snelle afbraak cancerogenen Recap: Carbohydrates contain carbon, hydrogen and oxygen in a 1-2-1 ratio. Simple sugars such as glucose provide immediate energy for cells. Complex carbohydrates called polysaccharides store energy (in animals and plants) and provide structural support (in plants).
2.7 Lipids: insoluble in water • •
Lipids include fats and oils, phospholipids and steroids. Lipids are insoluble in water. Fats store energy. Phospholipids and cholesterol are important structural components of the cell membrane. The sex hormones are steroids synthesized from cholesterol.
2.7.1 Triglycerides are energy-storage molecules • Triglyceriden slaan energie op o Vetten Glycerol + 3 “fatty acids” (koolwaterstof met carboxylgroep (COOH)) o 2 soorten Verzadigde vetten • 2 H-atomen per C-atoom • Rechte staarten • Vaste toestand bij kamertemperatuur • Cardiovasculaire ziekten Onverzadigde vetten (oliën) • > 2 H-atomen per C-atoom • Knikken in staart • Vloeibaar bij kamertemperatuur o Opgeslagen in vetweefsel Recap: lipids (triglycerides, phospholipids and steroids) are all relatively insoluble in water. Triglycerides are an important source of stored energy.
2.7.2 Phospholipids are the primary component of cell membranes • Fosfolipiden: primair bestanddeel van celmembranen o Gewijzigde vorm van lipiden o Structuur Glycerol 2 “fatty acids” 3e “fatty acid” verplaatst door negatief geladen groep: PO4- + positief geladen groep o Een uiteinde polair (hydrofiel), ander uiteinde neutraal (hydrofoob) 2.7.3 Steroids are composed of four rings • Steroïden bestaan uit 4 ringen o Structuur Drie 6-voudige ringen Één 5-voudige ring o Onoplosbaar in water o Vb. Cholesterol Verantwoordelijk voor oestrogeen en testosteron Recap: Phospholipids, an important component of cell membranes, have a polar (water-soluble) head and two fatty acid (water-insoluble) tails. Steroids, such as cholesterol, have a four ring structure.
2.8 Proteins: Complex structures constructed of amino acids • Aminozuren o Structuur Aminogroep (NH3) aan ene uiteinde Carbonzuur aan andere uiteinde C-H groep in het midden Bijkomende groep “R” •
Proteïnen gevormd door condensatiereactie o Ploypeptide langer dan 100 aminozuren o Complexe structuren en functie
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4 niveaus e o 1 structuur Aminozuur volgorde e o 2 structuur Oriëntatie in ruimte α-helix (rechtsdraaiende spiraal) β-sheet (plaatvormig) o 3e structuur 3-D vorm Neutrale aminozuren langs binnenkant, polaire langs buitenkant o 4e structuur Aantal polypeptideketens o Waterstofbindingen in 2e en 3e structuur Zeer zwak Kunnen van vorm veranderen
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Functies o Structurele steun o Spiercontractie o Celmembraan informatie en materiaal doorgeven o Enzymen biochemische reacties in cellen regelen
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Denaturatie o Permanente verstoring van structuur verlies van biologische functie o Door hoge temperatuur of verandering in PH •
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Proteins have unique three-dimensional structures that depend on their primary structure (their amino acid sequences). Living organisms construct a tremendous number of different proteins using just 20 different amino acids. The human body contains thousands of proteins, each with a different function. Enzymes are proteins that facilitate the rates of chemical reactions.
Recap: Proteins are complex molecules consisting of strings of amino acids. The function of a protein relates to its shape, which is determined by its amino acid sequence and the twisting and folding of its chain of amino acids. A denatured protein loses its shape and function.
2.8.1 Enzymes facilitate biochemical reactions • Enzymen = biologische katalysator o Versnellen chemische reacties; reagentia eindproducten o Van vorm veranderen Recap: Enzymes are proteins that facilitate biochemical reactions in the body. Without enzymes, many biochemical reactions would occur too slowly to sustain life.
2.9 Nucleic acids store genetic information • DNA (desoxyribonuceïneuur) en RNA (ribonucleïnezuur) o DNA RNA Eiwitten o Opgebouwd uit nucleotiden Suiker met 5 C-atomen (ribose in RNA, Desoxyribose in DNA) Base 1 of meerdere fasfaatgroepen o 4 basen Thymine (uracil in RNA) Adenine Cytosine Gunanine o RNA: enkelvoudige streng, is korter (enkel stuk dat codeert voor eiwitten) • •
DNA is composed of two long strands of nucleotides intertwined into a double helix. DNA is constructed from just four different DNA nucleotides. RNA is a shorter single strand of RNA nucleotides, representing the code for one or more proteins
Recap: DNA and RNA are constructed of long strings of nucleotides. Double stranded DNA represents the genetic code for life, and RNA is responsible for carrying out those instructions.
2.10 ATP carries energy • ATP draagt erengie o ATP (adenosine trifosfaat) Adenine + 2 extra fosfaatgroepen o ATP ↔ ADP + Pi + energie o ADP (adenosine difosfaat) •
The nucleotide ATP is an energy source for cells. The energy is stored in the bonds between phosphate groups.
ATP is a nearly universal source of quick energy for cells. The energy is stored in the chemical bonds between phosphate groups.
Hoofdstuk 3: Structure and Function of Cells 3.1 Cells are classified according to their internal organization • •
All cells have a plasma membrane that surrounds and encloses the cytoplasm Eukaryotic cells have a nucleus
3.1.1 Eukaryotes have a nucleus, cytoplasm and organelles • Eukaryoten o Plasma membraan Buitenste laag o Nucleus (celkern) Genetisch materiaal opgeslagen Informatiecentrum o Cytoplasma Alles binnen cel, uitgezonderd celkern Bestaat uit cytosol Bevat organellen gespecialeerde functies 3.1.2 Prokaryotes lack a nucleus and organelles • Prokaryoten o Bacteriën o Plamsamembraan o Geen celkern en organellen 3.2 Cell structure reflects cell function • Taken van cel o Ruw materiaal verzamelen o Afval uitscheiden o Macromoleculen o Groeien en reproduceren • •
Limits of cell size are imposed by the mathematical relationship between cell volume and cell surface area. Various types of microscopes with magnifications up to 100 000-fold enable us to visualize cells and their structures.
Recap: Common features of nearly all eukaryotic cells are plasma membrane, a nucleus, organelles and the cytoplasm. Differences in cell shape and internal organization reflect differences in function.
3.2.1 Cells remain small to stay efficient • Klein efficiënt o Metabolische activiteit evenredig met volume cytoplasma Elke cel heeft ruw materiaal nodig evenredig met volume Afval uitscheiden o Materiaal kan enkel binnengaan / buitengaan via plasmamembraan o Volume gaat rapper omhoog dan oppervlakte • Microvilli o Microscopische uitstulpingen plasmamembraan o Vergroten oppervlakte
Recap: cells exchange materials with their environment across their plasma membrane. Cells divide to remain small, because the makes them more efficient at obtaining nutrients and expelling wastes.
3.3 A plasma membrane surrounds the cell • Functie o Sommige stoffen doorlaten o Andere tegenhouden •
The plasma membrane is a bilayer of phospholipids that also contains cholesterols and various proteins.
3.3.1 The plasma membrane is a lipid bilayer • Structuur o 2 lagen fosfolipiden Polaire kop (hydrofiel, wateroplosbaar) Apolaire start (hydrofoob) naar midden gericht Geen specifieke plaats binnen plasmamembraan (drijven rond) o Cholesterol Zorgt voor stijfheid o Proteïnen Zorgen voor middelen om molecules en informatie te transporteren doorheen plamsamembraan Één regio elektrisch neutraal, andere geladen contact met water Geen specifieke plaats binnen plasmamembraan (drijven rond) Recap: the plasma membrane allows some substances to move into and out of the cell but restricts others. Its phospholipid bilayer contains cholesterol for rigidity and proteins for information transfer, transport of molecules and structural support.
3.4 Molecules cross the plasma membrane in several ways •
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Some molecules are transported across the plasma membrane passively (by diffusion), whereas others are transported by active processes requiring the expenditure of energy. Receptor proteins transfer information across the plasma membrane. The sodium-potassium pump is a plasma membrane protein with a critical role in the maintenance of cell volume
3.4.1 Passive transport: principles of diffusion and osmosis • Passief transport o Geen energie nodig o Diffusie Verschil in concentratiegradiënt Molecule: hoge concentratie lage concentratie Water: lage concentratie hoge concentratie Door lipide dubbellaag • Alleen wateroplosbare molecules geen elektrisch geladen • 2 belangrijkste: O2 en CO2 Door kanalen • Grootte, vorm en elektrische geladenheid van kanalen bepaalt welke moleculen kunnen passeren
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Sommige zijn gated gaan open onder bepaalde voorwaarden o Transport van ionen in cellen die elektrisch prikkelbaar zijn
Osmose Diffusie door semipermeabele wand Facilitated diffusion Molecule bindt aan transport proteïne Zeer selectief
Recap: Molecules diffuse from a region of higher concentration to a region of lower concentration. The net diffusion of water across a selectively permeable membrane is called osmosis.
3.4.2 Passive transport moves with the concentration gradient Recap: Diffusion and facilitated transport are both forms of passive transport. They do not require the expenditure of energy.
3.4.3 Active transport requires energy • Actief transport o Energie nodig ATP o Tegen concentratiegradiënt in o Proteïnen pompen, vb. Na-K-pomp 3.4.4 Endocytosis and exocytosis move materials in bulk • Endo- en exocytose o Vesikel met receptoren die enkel aan bepaalde moleculen binden o Fuseren met celmembraan 3.4.5 Information can be transferred across the plasma membrane • Informatie kan doorgegeven worden doorheen plasmamembraan o Receptorproteïnen o Molecule bindt aan specifieke receptor biochemische gebeurtenissen veranderingen in cel o Zeer selectief 3.4.6 The sodium-potassium pump helps maintain cell volume • De Na-K-pomp o Plasmamembraan: geen hoge druk weerstaan Concentratie binnen cel even groot als concentratie van extracellulairvocht o Werking 3 bindingsplaatsen voor NA Afbraak van ATP ADP Energie: pomp van vorm veranderen Na eruit, 2 bindingsplaatsen voor K Van vorm veranderen K in cel
3.4.7 Isotonic extracellular fluid also maintains cell volume • Osmotische druk o Isotoon Gelijke druk o Hypertoon Concentratie in cel hoger dan in extracellulair vocht water diffuseren uit cel Cel krimpen en sterven o Hypotoon Concentratie in cel lager van in extracellulair vocht water diffuseren in cel Cel opzwellen en ontploffen Recap: The Sodium-potassium pump is an essential mechanism in the regulation of cell volume. In addition, homeostatic regulatory processes keep the tonicity of the extracellular fluid relatively constant.
3.5 Internal structures carry out specific functions • • • •
The nucleus directs all of the cell’s activities Ribosomes, the endoplasmic reticulum and the Golgi Apparatus participate in the synthesis of life’s molecules Vesicles are membrane-bound spheres that transport, store and ship cellular products and toxic or dangerous materials. Mitochondria make energy available for the cell in the form of high-energy molecule ATP.
3.5.1 The nucleus controls the cell • Nucleus o Genetisch materiaal: DNA o Nucleair membraan omsluit DNA o Nucleair poriën: laten sommige molecules door, maar niet DNA o Nucleolus: synthese RNA en proteïnen ribosomen 3.5.2 Ribosomes are responsible for protein synthesis • Maken van specifieke proteïnen • In cytosol of vast aan endoplasmatisch reticulum o Cytosol proteïnen voor onmiddellijk gebruik o Endoplasmatisch reticulum proteïnen uitgescheiden 3.5.3 The endoplasmic reticulum is the manufacturing center • Endoplasmatisch reticulum o Synthese chemische componenten gemaakt door cel o Ruw ER: ribosomen Synthese proteïnen o Glad ER Synthese andere macromoleculen Verpakken proteïnen en lipiden voor transport naar Golgi-apparaat Recap: The nucleus contains most of the cell’s genetic material. Ribosomes composed of RNA and ribosomal proteins assembly. The endoplasmic reticulum modifies some of the proteins, manufactures most other macromolecules in rough form, and transfers them to Golgi apparatus.
3.5.4 The Golgi apparatus refines, packages and ships • Golgi-apparaat o Afwerking (door enyzmen), verpakking (vesikels) verzending 3.5.5 Vesicles: Membrane-bound storage and shipping containers • Vesikels o Omvatten iets in cel o Verzending en opslag Producten ER en Golgi-apparaat Inhoud bepaald door proteïnen in vesikel membraan o Export Exocytose Golgi-apparaat o Enocytose Bacteriën en ruw materiaal van extracellulaire omgeving o Peroxisomen en lysosomen Blijven in vesikel om schade aan cel te voorkomen Peroxisomen • Vernietigen giftige afvalstoffen in cel Lysosomen • Vernietigen bacteriën en andere grote objecten • Opruimen beschadigde mitochondriën en andere cellulair afval • Na taken: reidual bodies exocytose Recap: The Golgi apparatus refines cellular products to their final form and packages them in membranebound vesicles. Some vesicles store, ship and secrete cellular products; others digest and remove toxic waste and cellular debris.
3.5.6 Mitochondria provide energy • Mitochondriën o Zorgen voor energie o Aantal in cel hangt af van energiebenodigdheid cel o Structuur Glad buitenste membraan Binnenste membraan met plooien Proteïne-enzymen kakatlysator 3.5.7 Fat and glycogen: sources of energy • Vet en glycogenen o Bronnen van energie o Glycogenen produceren rapper ATP dan vet. Recap: Mitochondria manufacture ATP for the cell. Some cells stockpile fats or glycogen, which they can use to make more ATP as needed.
3.6 Cells have structures for support and movement • •
A cytoskeleton of microtubules and microfilaments serves as structural support and anchors the various organelles. Cilia and flagella provide for movement in certain types of cells. Both cilia and flagella are made of pairs of protein microtubules.
3.6.1 The cytoskeleton supports the cell • Cytoskelet o Structuur Microtibuli Microfilamenten Verbinden met mekaar en glycoproteïnen o Functie Steun 3.6.2 Cilia and flagella are specialized for movement • Cilia en flagella o Structuur Proteïne microtibuli Omringd door plasmamembraan Bijeengehouden door verbindingen (energie nodig) o Functie Cilia • Materiaal langs omtrek van cel Flagellum • Alleen bij spermacel 3.6.3 Centrioles are involved in cell division • Centriolen o Celdeling Recap: The cytoskeleton forms a supportive framework for the cell. Cilia and flagella are specialized for movement, and centrioles are essential to cell division.
3.7 Cells use and transform matter and energy • Metabolisme o Som van alle chemische reacties in organisme o Metabolische paden Lineair • Eindproduct ene chemische reactie substraat andere chemische reactie Cyclisch o 2 soorten Anabolisme • Opbouw • Energie nodig Catabolisme • Afbraak • Geeft energie vrij o Bijna elke chemische reactie: specifieke enzymen o Metabolische activiteit vraagt veel energie o ATP ↔ ADP + Pi + energie
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The creation and destruction of molecules either requires energy or liberates energy The most rapidly useful form of energy for cells is ATP. The production of ATP from glucose requires four consecutive stages: glycolysis, a preparatory step, the critic acid cycle and the electron transport system Cells can utilize glycogen, fats or proteins fer energy. Only a small amount of ATP can be made in the absence of oxygen.
Recap: Metabolism refers to all of cell’s chemical processes. Metabolic pathways either create molecules and use energy (anabolism) or break them down and liberate energie (catabolism)
3.7.1 Glucose provides the cell with energy • C6H12O6 • 1 molecule glucose 36 molecules ATP • 4 stages o Glycolysis Glucose 2 C3H4O3 (pyrodruivenzuur) Energie nodig o Preparatory step Pyrodruivenzuur in mytochondrie Acetyl CoA + energie o Citroenzuurcyclus Acetyl CoA afgebroken Energie komt vrij o Electron Transport system ADP ATP 3.7.2 Fat and proteins are additional anargy sources • Vetten en proteïnen o Vetten: 2 keer meer energie dan carbohydrate Triglyceriden glycerol + vette zueren Glycerol glucose of pyrodruivenzuur Vette zuren 2 carbon-actylgroepen o Proteïnen Proteïnen aminozuren Aminogroep (NH2) verwijderd Vooral tijdens hongersnood spieren verzwakken 3.7.3 Anaerobic pathways make energy available without oxygen • Anaerobisch o Glucose pyrodruivenzuur o Pyrodruivenzuur melkzuur Branderig gevoel en krampen o Slechts 2 molecules ATP per molecule glucose Recap: carbohydrates and fats are the main sources of stored energy for making ATP, although proteins can be used if necessary. In the absence of oxygen, only glucose can be used, and only very limited amounts of ATP are produced.
Hoofdstuk 4: From Cells to Organ Systems 4.1 Tissues are groups of cells with a common function • Weefsels zijn een groep cellen met dezelfde functie o Multicellulair organisme Veel cellen die collectief de functies van leven delen Voordelen • Groter (eten ipv gegeten worden) • Gunstige omgeving om te leven zoeken o Specialisatie Georganiseerd Geïntegreerd • Weefsels o Groep gespecialiseerde cellen met dezelfde vorm & functies o 4 soorten Epitheel of dekweefsel Bindweefsel Spierweefsel Zenuwweefsel •
The four types of tissues are epithelial tissue, connective tissue, muscle tissue, and neural tissue
4.2 Epithelial tissues cover body surfaces and cavities • Dekweefsel o Bedekt oppervlakken & lichaamsholtes o
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Functies Bescherming onderliggende weefsels Glad wrijving reduceren Materialen transporteren Absorberen water & voedingsstoffen in bloed Scheiden afvalproducten uit Sommige: lichaamsklieren Exocrien Endocrien Epithelial tissues are sheets of cells that cover of line body surfaces and form the glands. Epithelial tissues are supported by a noncellular layer called the basement membrane.
4.2.1 Epithelial tissues are classified according to cell shape • Geordend volgens vorm o Squamous epitheel Afgeplatte cellen Voorbeelden • Buitenste laag huid • Binnenste laag bloedvaten, longen, mond & keel, vagina Cuboidal epitheel • Kubusvormige cellen • Voorbeelden o Nierbuis o Eierstokken Columnar epitheel • Grote, rechthoekige cellen • Voorbeelden o Spijsverteringsstelsel o Sommige reproductieorganen o Strottenhoofd o Goblet cells scheiden slijm af o Single <-> stratified 4.2.1 The basement membrane provides structural support • Onderste membraan zorgt voor structurele steun o ‘basement membrane’ Niet-cellulair Bestaat uit proteïnen afgescheiden door epitheelcellen o Epitheelcellen verbonden met elkaar door cell junctions Thight • Niets kan passeren • Controleren beweging materie • Voorbeelden o Spijsverteringsstelsel o Blaas o Nierbuizen Adhesion • Stretchen & buigen • Epithelium van huid Gap • Beweging van ionen & water tussen 2 aangrenzende cellen • Voorbeelden o Lever o Hart o Sommige spierweefsels Recap: Epithelial tissues line body surfaces and cavities, and form glands. They are classified according to cell shape (squamous, cuboidal, or columnar) and the number of cell layers (simple of stratified).
4.3 Connective tissue supports and connects body parts • Bindweefsel o Functies Ondersteunt zachtere organen Verbindt delen van lichaam Opslaan vet Productie bloedcellen o
Structuur Weinig levende cellen Matrix = niet-levend materiaal
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Fibrous connective tissues contain several types of extracellular fibers and only a few living cells. They support and connect body parts. Cartilage, blood, bone , and adipose tissue are classified as special connective tissues.
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4.3.1 Fibrous connective tissues provide strength and elasticity • Fibreus bindweefsel o Functie Verbindt verschillende lichaamsdelen Zorgt voor kracht, steun & flexibiliteit o Soorten vezels Collageen • Proteïnen • Kracht & flexibiliteit Elastisch • Proteïne elastin • Stretchen Reticulair • Proteïn collageen • Ondersteuning zachte organen
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Bindweefsel Structuur • Water, polysacchariden, proteïnen • Fibroblasten o Produceren & afscheiden proteïnen Soorten • Losmazig (areolar) o Weinig collageenvezels & elastische vezels o Flexibiliteit + beetje kracht • Straf o Meer collageenvezels o Sterkste bindweefsels als in zelfde richting als vezels o Zeer weinig bloedvaten • Elastisch o Rond organen die van vorm/grootte veranderen Maag Blaas stembanden o Elastische vezels • Reticulair o Ondersteuning organen o Reticulaire vezels
Recap: Fibrous connective tissues hold body parts together. Fibrous connective tissues contain extracellular fibers of strong but flexible proteins, a few living cells, and a ground substance of polysaccharides, proteins, and water.
4.3.2 Specialized connective tissues serve special functions • Gespecialiseerde bindweefsels o Kraakbeen Functie • Beenvorming • Beschermt gewrichten Structuur • Collageenvezels met meer water door chondroblasten • Omringd door lacunae • Geen bloedvaten trage genezing o Been Calcium & fosfaat Vele bloedvaten o Bloed Bloedcellen komen van stamcellen in been Rode bloedcellen: transport Witte bloedcellen: immuunsysteem Vetweefsel Vetopslag Opgebouwd uit vetcellen Aantal genetisch bepaald Recap: Among the specialized connective tissues, cartilage and bone provide support, blood transports materials throughout the body, and adipose tissue stores energy in the form of fat.
4.4 Muscle tissues contract to produce movement • Spierweefsel trekt samen om beweging te produceren o Structuur Spiervezels Parallel Cytoplasma: proteïnen 4.4.1 Skeletal muscles move body parts o Skeletspieren Structuur • Aanhechting aan pezen bot • Veel kerncellen • Individuele vezels, parallel naast elkaar Functie • Lichaamsdelen bewegen Vrijwillig
4.4.2 Cardiac muscle cells activate each other o Hartspieren Structuur • Kortere vezels, parallel naast elkaar • 1 celkern • Gap junctions tussen cellen • Elektrische connecties Onvrijwillig • • 4.4.3 •
Muscle tissue is composed of either skeletal, cardiac, or smooth muscle cells. Skeletal muscles are attached to bones by tendons.
Smooth muscle surrounds hollow structures Glad spierweefsel o Rond organen & buizen o Structuur Kleiner dan skeletspieren 1 celkern Parallel naast elkaar Gap junctions elektrische connecties o Onvrijwillig
4.5 Nervous tissue transmits impulses • Structuur o Gespecialiseerde cellen genereren & doorsturen elektrische impulsen: neuronen 3 delen • Cellichaam met celkern • Dendrieten • Axonen o Gliacellen Omringen & beschermen neuronen Voedinsstoffen • Locatie o Hersenen o Ruggengraat o Zenuwen • •
Neurons are specialized for conduction of electrical impulses. Glial cells surround and protect neurons and supply them with nutrients.
Recap: The common feature of all muscle tissues (skeletal, cardiac, and smooth) is that they contract, producing movement. Nervous tissues serve as a communication network by generating and transmitting electrical impulses.
4.6 Organs and organ systems perform complex functions • Organen o Structuren van 2 of meer soorten weefsel die een specifieke functie hebben • • •
The human body is composed of 11 organ systems, each of which has at least one broad function. Membranes consisting of layers of epithelial and connective tissues line the body cavities. Positions of body parts are described on three planes: midsagittal, frontal, and transverse.
4.6.1 The human body is organized by organ systems • Orgaansystemen o Groepen organen die tesamen een brede functie vervullen die belangrijk is voor het overleven Recap: An organ consists of several tissue types that join together to perform a specific function. An organ system is a group of organs that share a broad function important for survival.
4.6.2 Tissue membranes line body cavities • Weefselmembraan: lichaamsholtes o Structuur Laag dekweefsel Laag bindweefsel o Soorten Serous wrijving verminderen Mucous vreemde partikels verwijderen Synovial gewrichten smeren Cutaneous huid 4.6.3 •
Describing body position or direction Lichaamsposities o Anterior (vanvoor) <-> posterior (vanachter) o Proximal (dichter) <-> distal (verder) o Superior (boven) <-> inferior (onder)
Recap: The body’s hollow cavities are lined by tissue membranes that support, protect, and lubricate cavity surfaces. Locations of cavities and body parts are described relative to three planes (midsagittal, frontal, and transverse), using pairs of directional terms such as “anterior” and “posterior”.
4.7 The skin as an organ system •
• •
The skin functions as a protective barrier, participates in the maintenance of homeostasis, and provides us with sensory information about the external environment. Skin has two layers: an outer epithelial layer called the epidermis and an inner connective tissue layer called the dermis Skin also contains nerves, blood vessels, glands, hair follicles, and smooth muscle.
4.7.1 Skin had many functions • Functies o Bescherming tegen uitdroging o Bescherming tegen verwonding o Bescherming tegen bacteriën & virussen o Regulatie lichaamstemperatuur o Synthese inactieve vorm vitame D o Sensatie: informatie van buitenwereld 4.7.2 Skin consists of epidermis and dermis • Structuur o Buitenste laag = epidermis Epitheelweefsel • Squamous cells • Altijd vernieuwd o Weinig bloedvaten o Snelle heling • Keratinocytes o Productie keratine o Waterproof o Basal cells • Melanocytes o Melanin: pigment o Bescherming tegen UV-straling o Middelste laag = hypodermis Bindweefsel Vetcellen o Binnenste laag = dermis Straf bindweefsel Papillae: zenuwuiteinden & bloedvaten Haar Glad spierweefsel Talgklieren Zweetklieren Bloedvaten Zenuwuiteinden Recap: The Skin is an organ because it consists of different tissues serving common functions. Functions of skin include protection, temperature regulation, vitamin D synthesis, and sensory reception.
4.8 Multicellular organisms must maintain homeostasis • Interne omgeving : interstitual fluid o Voedingsstoffen voor cellen o Constant blijven • • • • •
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In a milticellular organism, the external environment of every cell is the internal environment of the organism Relative constancy of the internal environment of the organism is called homeostasis. Homeostasis is maintained by negative feedback control systems. In a negative feedback control system, a change in the controlled variable sets in motion a sequence of events that tends to reverse (or negate) the initial change. In the regulation of body temperature, sensors located throughout the body send information about temperature to the control center, located in the hypothalamus of the brain. Possible responses to a change in body temperature include dilating or constricting the blood vessels to the skin, shivering (if temperature is too low), and sweating (if temperature is too high).
4.8.1 • •
Effector homeostasis is maintained by negative feedback Negatieve feedback controleert homeostase Werking o Controlled variable o Sensor (receptor) Zendt informatie naar control center o Control center: set point
4.8.2 •
Negative feedback helps maintain core body temperature Voorbeeld: lichaamstemperatuur o Controlled variable: temperatuur in centrum van lichaam o Sensor: huid & interne organen o Control center: hypothalamus o Effector Beneden set point • Bloedvaten vernauwen • Skeletspieren beven Boven set point • Bloedvaten uitzetten • Zweten o Opmerkingen Meerdere sensoren tegelijkertijd is mogelijk Control center integreert alle informatie & geeft gepaste respons Meerdere effectoren is mogelijk
4.8.3 •
Positive feedback amplifies events Positieve feedback versterkt gebeurtenissen o Bv. Geboorte
Recap: All multicellular organisms must maintain homeostasis of their internal environment. In a negative feedback control system, any change in a controlled variable sets in motion a series of events that reverse the change, maintaining homeostasis.
Hoofdstuk 5: The Skeletal System 5.1 The skeletal system consists of connective tissue • Botten o Structuur Niet-levend materiaal: kristallen van calcium mineralen Levend materiaal • Cilindrisch middenstuk: diaphysis o Dicht, compact been aan uiteinde Osteons osteocytes calciumfosfaat Osteocytes in lacunae Contact met elkaar via canaliculi o Centrale holte: geel beenmerg vet • Grote knobbel uiteinde: epiphysis o ‘spongy bone’ met trabeculae (calcium mineralen) o Soms rood beenmerg: stamcellen • Buitenste laag: bindweefsel periosteum Zenuwen Bloedvaten o Functie Steun & aanhechting skeletspieren Beweging door interactie met spieren Bescherming van interne organen Vorming van bloedcellen Mineraalopslag: calcium & fosfaat metabolisme • • • •
Connective tissues of the skeletal system are bones, ligaments, and cartilage. Bone is a living tissue composed of cells and extracellular material. Ligaments, composed of dense fibrous connective tissue, attach bones to each other. Cartilage forms the intervertebral disks and lines the points of contact between bones.
5.1.1 Bones are the hard elements of the skeleton Recap: Bones contribute to support, movement, and protection. They also produce the blood cells and store minerals.
5.1.2 Bone contains living cells Recap: Bone may be compact or spongy in appearance. Long bones have a hollow shaft of compact bone filled with yellow marrow; spongy bone with red bone marrow is found in the epiphyses.
5.1.3 •
Ligaments hold bones together Ligamenten o Functie Benen verbinden Beweging o Structuur ‘dense fibrous’ bindweefsel
5.1.4 Cartilage lends support • Kraakbeen o Functie Steun onder druk Beweging o Soorten Fibreus kraakbeen • Collageenvezels • Weerstaat spanning & druk Hyalien kraakbeen • Dunne collageenvezels • Embryonische structuren die later been worden • Bedekt uiteinde volwassen botten Elastisch kraakbeen • Elastische vezels • Buigbaar 5.2 Bone development begins in the embryo • After about two months of fetal development, rudimentary models of bones have been formed from cartilage. • Throughout the rest of fetal development and on into childhood, bone-forming cells called osteoblasts replace the cartilage model with bone. • Growth in the length of long bones centers on growth plates in each epiphysis •
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Ossificatie (2 – 3 maanden) o Chondroblasten (kraakbeen) vervangen door been o Matrix chrondroblast bloedvaten: osteoblasten Osteoid (mix van proteïnen) interne structuur & kracht van botten Hydroxyapatite kristallisatie harde mineralen Groeiplaat (adolescentie) o Activiteit chondroblasten aan buitenkant plaat o Gecontroleerd door hormonen Groeihormoon Sekshormoon
Recap: Bone-forming cells called osteoblasts produce a protein mixture (including collagen) that becomes bone’s structural framework. They also secrete an enzyme that facilitates minerals deposition within the protein matrix.
5.3 Mature bone undergoes remodeling and repair • 3e type beencellen: osteoclasten oplossen van bot • • •
Bone undergoes replacement throughout life. Bones can change shape over time, depending on the forces to which they are exposed. The process of bone repair includes: (1) the formation of a hematoma, (2) the formation of a fibro cartilage callus that binds the broken ends together, and (3) the eventual replacement of the callus with new bone.
5.3.1 •
Bones can change in shape, size and strength Veranderen van vorm, grootte & kracht o Druk op been elektrische stroom activiteit osteoblasten Nieuw been gevormd onder hoge druk Been opgelost onder lage druk o Osteoporose: geen balans been gaat massa verliezen
5.3.2 •
Bone cells are regulated by hormones Gecontroleerd door hormonen o Calcium homeostase o Beneden set point parathyroid hormone (PTH) Activiteit osteoclasten calcium & fosfaat in bloedbaan o Boven set point calcitonin Activiteit osteoblasten calcium & fosfaat gebruikt om been te vormen
5.3.3 •
Bones undergo repair Herstelling o Hematoma Massa gestold bloed Ontsteking, zwelling & pijn o Fibroblasten chondroblasten callus osteoclasten (verwijderen dode fragmenten been & bloedcellen hematoma) osteoblasten (callus omzetten in been) o Ietsje dikker dan normaal been o Elektrische stroom kan versnellen Aantrekken van osteoclasten & osteoblasten
5.4 The skeleton protects, supports, and permits movement • 4 soorten bot o Korte: even breed als lang o Plat: kleine hoeveelheid spongy bone o Onregelmatig o Lang • • •
The axial skeleton is represented by the skull, the vertebral column, the sternum, and the ribs. In the vertebral column, intervertebral disks of fibrocartilage absorb shock and permit limited movement The appendicular skeleton includes the pectoral gridle, the pelvic gridle, and the upper and lower limb
5.4.1 The axial skeleton forms the midline of the body • Axiaal skelet o Schedel Bescherming hersenen Zie figuur 5.6 in handboek Sinusen: holtes • Toon & resonantie stem • Afscheiding slijm • Sinusitis o Wervelkolom Functies • Steun hoofd • Bescherming ruggengraat • Aanhechtingsplaats Structuur: van boven naar onder • 7 nekwervels • 12 borstwervels • 5 lendenwervels • Heiligbeen (vergroeiing van 5 wervels) • Staartbeentje (vergroeiing van 4 wervels) Aanliggende wervels gescheiden door intervertebrale schijf • Verschuiving hernia o Ribben & borstbeen Functie • Borstholte beschermen • Ademhaling: borstbeen vastgehecht aan middenrif Structuur • 12 paar ribben o Bovenste 7 via kraakbeen aan borstbeen o Rib 8-10 via kraakbeen aan 7e rib o Onderste 2: zwevende ribben Recap: The skull protects the brain, the vertebral column protects the spinal cord and supports the appendicular skeleton, and the rib cage protects the organs of the chest cavity.
5.4.2 •
The appendicular skeleton: pectoral girdle, pelvic girdle, and limbs Appendiculair skelet o Schoudergordel Wat? • Halsbeen (sleutelbenen) • Schouderbladen Functie • Flexibiliteit aan bovenste ledematen Structuur • Aanhechting via spieren en pezen • Bovenarm o Opperarmbeen (humerus) • Onderarm o Spaakbeen (radius) o Ellepijp (ulna) • Vuist o 8 handwortelbeentjes • Handpalm o 5 middelhandsbeentjes • Vingers o 14 kootjes o Opponeerbare duimen Flexibiliteit instabiliteit • Bv. Carpal tunnel syndroom o Pijn, tintelingen, gevoelloosheid
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Bekkengordel Wat? • Heiligbeen • Staartbeen • Linker- & rechterheupbeen Functie • Steun aan bovenlichaam (zwaartekracht) • Aanhechtingsplaats voor benen • Bescherming organen • (zwangerschap & geboorte) Structuur • Dijbeen o Langste & sterkste been o Knie heup • Scheenbeen (tibia) o Knie enkel o Voorste been • Kuitbeen (fibula) o Vastgehecht aan scheenbeen o Achterste been o Knie enkel • Knieschijf (patella) • Enkel & voet o 7 voetwortelbeentjes o 5 middelvoetsbeentjes o 14 kootjes
Recap: The pectoral girdle and upper limbs are capable of a wide range of motions (dexterous movement). The pelvic girdle supports the body’s weight and protects the pelvic organs. The lower limbs are strong but less dexterous than the upper limbs.
5.6 Diseases and disorders of the skeletal system • Sprains are the result of stretched or torn ligaments. Bursitis and tendinitis are caused by injuries to the bursae and tendons. • Arthritis is a general term for joint inflammation. • Osteoarthritis is a condition in which the cartilage covering the ends of the bones wears out and joint friction increases • Osteoporosis is a condition caused by progressive bone loss over time.
5.6.1 •
Sprains mean damage to ligaments Verstuiking o Oorzaak: verrokken of gescheurde ligamenten o Symptomen Soms interne bloeding Latere kneuzing Zwelling Pijn o Kleinere ligamenten genezen vanzelf, anders operatie om weg te halen
5.6.2 •
Bursitis and tendinitis are caused by inflammation Slijmbeursontsteking & peesontsteking o Ontsteking van slijmbeurs of pees o Oorzaken Verwondingen aan pezen Fysieke schade door klap op gewricht Bacteriële infectie o Verzorging Genezen traag Koud eerste 24 uur Daarna warm
5.6.3 Arthritis is inflammation of joints • Artritis o Ontsteking van gewrichten o Bv. Osteoartritis (artrose) Kraakbeen verdwijnen Gewrichten minder soepel Oplossing • Operaties • Medicatie • Regelmatige beweging o Bv. Reumatoïde artritis (gewrichtsreumatiek) Ontsteking gewrichten Veroorzaakt door eigen immuunsysteem
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Osteoporose o Symptomen Kromme houding Moeite stappen Beenfracturen o Oorzaak: imbalans tussen osteoclasten & osteoblasten beenmassa verliezen o Risico’s Oudere vrouwen (daling oestrogeen vanaf menopauze) Rokers Zittende levensstijl Lage calcium inname Ondergewicht o Voorkomen Genoeg calcium & vitamine D Consequente beweging
Hoofdstuk 6: The Muscular System
Hoofdstuk 7: Blood 7.1 The components and functions of blood • Blood consists of formed elements and plasma. Blood has transports, regulatory, and protective functions. • Plasma contains numerous plasma proteins involved in transport, regulation of water balance, and protection. It also contains ions, hormones, nutrients, wastes and, gases. • Erythrocytes (RBCs) are highly specialized for the transport of oxygen, but they also transport some carbon dioxide. • Hemoglobin is the primary protein in red blood cells and gives blood its oxygen-carrying capacity. • The formed elements of blood all originate from stem cells in red bone marrow • Leukocytes (WBCs) defend the body against disease and the effects of injury. • RBCs and WBCs have short life spans and must continually be replaced. RBC production is stimulated when the body detects low oxygen levels in the blood. • Platelets are cell products that participate in blood hemostasis. •
Functies o Transport o Regulatie homeostase o Verdediging
Recap: About 8% of our body weight is blood. Blood maintains homeostasis by (1) transporting nutrients and exporting wastes, (2) regulating temperature and water volume, and (3) carrying molecules that fight disease and promote healing.
7.1.1 •
Plasma consists of water and dissolved solutes Plasma o 90% water o Proteïnen Albumins • Regulatie waterbalans Globulines • Transport verschillende materie • Beta-globulines binden aan vet o LDL (slechte cholesterol) <-> HDL • Gamma-globulines immuunsysteem Clotting proteins o Elektrolyten Celfunctie & celvolume o Hormonen Transport van informatie o Voedingsstoffen o Afvalproducten o Gassen metabolisme
Recap: about 55% of whole blood consists of plasma. Plasma is mostly water and serves as the medium in which all other blood components are dissolved and transported. Plasma proteins include albumins, globulins, and clotting factors.
7.1.2 •
Red blood cell transport oxygen and carbon dioxide Rode bloedcellen (erytrocyten) o Functies Dragers van O2 & CO2 Geven bloed kleur Zorgen voor viscositeit o Structuur Lijken op donut: voordelen • Flexibel • Geen enkel deel is ver van celoppervlak vergemakkelijkt gasuitwisseling Geen celkern Geen organellen Hemoglobin binding zuurstof • 4 polypetidekettingen • Ijzeratoom = bindingplaats • Best als concentratie zuurstof hoog is & pH ongeveer neutraal • Hemoglobine + 4 O2-atomen = oxyhemoglobine (rood) o 4 zuurstofatomen afgegeven deoxyhemoglobine (paars) Geen mitochondrieën • Anaërobische energie • Bloeddoping meer zuurstof in bloed
Recap: the ability of RBCs to transport nearly all of the oxygen and some of the carbon dioxide in blood depends on hemoglobin, the primary protein within red blood cells. Each molecule of hemoglobin contains four atoms of iron that can bind reversibly to oxygen.
7.1.3 Hematocrit reflects oxygen-carrying capacity • Hematocriet = percentage rode bloedcellen in bloed o Laag anemie o Hoog bloedklonters, polycythemia o meer rode bloedcellen 7.1.4 all blood cells and platelets originate from stem cells • Afkomstig van stamcellen 7.1.5 RBCs have a short life span • Korte levensduur o Stamcellen onvolwassen cellen ‘erythoblasten’ + hemoglobin rode bloedcellen o 120 dagen o Macrofagen verwijderen dode RBC Fagocytose • Hemoglobine aminozuren proteïnen • Ijzeratomen rode beenmerg (recyclage) • Hemegroepen bilirubine o Geelzucht
7.1.6 •
RBC production is regulated by a hormone Geregeld door hormoon o Negatieve feedback Controlled variable: hoeveelheid zuurstof Sensor: cellen in nieren Effector: erythropotoietin Lage hoeveelheid: stamcellen
Recap: All blood cells and platelets are derived from stem cells in red bone marrow. RBCs have a short life span and must be continually replaced. The rate of production of RBCs is stimulated by the hormone erythropoietin, which is produced in the kidneys.
7.1.7 White blood cells defend the body • Witte bloedcellen (leukocyten) o Structuur Nucleus Geen hemoglobine Doorschijnend Afkomstig van stamcellen Kunnen van vorm veranderen o Functie Rol in immuunsysteem o Soorten Granulair • Granules • Groeien in rood beenmerg • Levensduur: paar uur – 9 dagen • Neutrofiele granulocyt o 60% van WBC o Eerste om infectie te bestrijden o Vooral bacteriën & schimmels • Eosinofiele granulocyt o Verdediging tegen grote parasieten o Vrijlaten van chemicaliën allergische reactie • Basofiele granulocyt o Zeldzaamste o Productie histamine onstekingsreactie Agranulaire leukocyten • Granules, niet zichtbaar • Sommigen rijpen in rood beenmerg, andere, T-lympocytes, in zwezerik • Monocytes o Grootste WBC o Actief tijdens chronische infecties o Differentiëren in macrofagen
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Lymphocytes o B-lymphocytes plasmacellen antilichamen o T-lymphocyten vernietigen bacteriën, virussen & kankercellen
7.1.8 Platelets are essential for blood clotting • Bloedplaatjes o Afkomstig van megakaryoblasten (stamcellen) o Circuleren niet o Levensduur: 5-9 dagen o Productie gecontroleerd door thrombopoietin 7.2 Hemostasis: stopping blood loss • Doel: bloedverlies stoppen • •
7.2.1 •
Hemostasis is a three-phase process that prevents blood loss through damaged vessels. The phases are (1) vascular spasm, (2) the formation of a platelet plug, and (3) blood clotting. During the formation of a blood clot, substances released by damaged blood vessels cause soluble proteins threads called fibrin. The threads form a interlocking mesh of fibers, trapping blood cells and sealing ruptured vessels. Vascular spasms constrict blood vessels to reduce blood flow Spasmen van bloedvaten o Samentrekken van bloedvaten o Duurt halfuur
Recap: white blood cells (leukocytes) defend the body against disease and injury. The activities of various leukocytes include participating in the response to tissue injury, producing antibodies, engulfing entire foreign cells, and releasing enzymes to attack foreign organisms too large to be engulfed whole.
7.2.2 •
Platelets stick together to seal a ruptured vessel Propvorming o Bloedplaatjes zwellen & klitten samen o Hechting aan beschadigde delen van vaatwand
7.2.3 •
A blood clot forms around the platelet plug Bloedstolling o Vloeibaar gel o Prothrombin activator omzetting van prothrombine in thrombine o Thrombine omzetting van fibrinogen in fibrinedraden
Recap: damage to blood vessels causes the vessels to spasm (contract) and the nearby platelets to become sticky and adhere to each other, limiting blood loss. In addition, a series of chemical events causes the blood in the area to clot, or coagulate (form a gel).
7.3 Human blood types • Antigenen & antilichamen o Eigen cellen zijn gemerkt met “zelf” o Andere cellen worden als vreemd aanzien & lokken immuunreactie uit = antigenen o Immuunreactie: productie van antilichamen (door lymphocyten gamma globulines) o Vorming van antigen-antilichaamcomplexen •
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Successful transfusion of blood form one person into another depends on compatibility of their blood types, which is determined by antibodies in plasma and surface antigens on red blood cells. Blood types are classified primarily on the basis of the ABO system and the presence or absence of the Rh factor. Rh factor in particular can affect certain pregnancies adversely.
Recap: different blood types are determined by the presence of surface antigens on red blood cells and the presence of antibodies to surface antigens other than their own.
7.3.1 ABO typing is based on A and B antigens • ABO systeem o Gebaseerd op antigenen A & B A: antigen A B: antigen B AB: antigenen A & B O: geen antigen Antilichamen tegen andere antigenen o Antigen-antilichaam-complexen bloedvaten blokkeren Meestal antilichamen van ontvanger die voor schade zorgen (kleine hoeveelheid antilichamen donor) Recap: Types A, B, AB, and O blood are indentified by the presence (or absence) of type A and/or B surface antigens on their red blood cells.
7.3.2 •
RH blood typing is based on Rh factor Rhesusfactor o Rh positief Rh antigen o Rh- moeder + Rh+ man + Rh+ baby moeder anti-Rh-lichamen produceren Kruisen placenta & vallen baby’s bloed aan Hemolytic disease of the newborn (HDN) • Mentale retardatie • Dood Hoger risico voor 2e baby Meestal komt bloed pas in contact tijdens geboorte Tegenwoordig: vaccins
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Overerfbaar: toepassingen o Migratie bepalen o Vaderschap o Criminele zaken
7.3.3 Blood typing and cross-matching ensure blood compatibility • Techniek om bloedgroep te bepalen o Plasma met A & B antigenen toevoegen aan bloed Klot antigenen die bij antilichaam passen o Over 100 andere bloed antigenen Zeldzaam Cross-matching • Donorbloed met plasma ontvanger mixen + bloed ontvanger met donorplasma mixen • Geen klot match Recap: in addition to ABO type, all persons are classified according to the presence or absence of another red blood cell surface antigen called the Rh factor. Rh factor antibodies can cause a serious immune reaction of the mother to her own fetus under certain circumstances.
7.4 Blood disorders • Anemia is a reduction in blood oxygen-carrying capacity for any number of reasons, including insufficient red blood cell production and excessive blood loss. • Leukemia is a cancer characterized by uncontrolled production of abnormal leukocytes (whit blood cells). • Mononucleosis is a contagious viral disease of lymphocytes and lymphatic tissue. • Blood poisoning is a general term for infection of blood plasma by various microorganisms. •
Hemofilie o Overerfbaar o Gebrek aan klottingsfactor o Bv. Hemofilie A missen klottingsfactor VIII
7.4.1 •
Anemia: Reduction in blood’s oxygen-carrying capacity Anemie: daling van capaciteit om zuurstof te dragen o Symptomen Bleke huid Hoofdpijn Moeheid Duizeligheid Moeilijk ademen Hartkloppingen o Soorten Ijzertekort • Meest voorkomende • Hemoglobine normaal 4 ijzeratomen • Oorzaken o Te weinig ijzer in eten o Spijsverteringsstelsel absorbeert geen ijzer • Genezing o Medicatie met ijzer o Eten rijk in ijzer Hemorrhagic • Bloedverlies door wonden Pernicious • Vitame B12-tekort Hemolytic • Vernietiging van rode bloedcellen • Oorzaken o Sikkelcelanemie o Malaria
7.4.2 Leukemia: uncontrolled production of white blood cells • Leukemie o Alle soorten bloedkanker Ongecontroleerde groei van abnormale/onvolwassen witte bloedcellen o 2 types Acuut Chronisch o Oorzaken Virus Straling/chemicaliën Genetische factoren o Symptomen Kneuzingen Bloedarmoede Hoofdpijn Vergrote lymfeknopen o Genezing Radiatie/chemo vernietigt ook stamcellen Beenmergtransplantatie 7.4.3 Multiple myeloma: uncontrolled production of plasma cells • Multipel myeloom o Soort kanker Abnormale plasmacellen in beenmerg ondergaan ongecontroleerde deling Belemmert productie antilichamen o Symptomen Weke botten Hoge calciumlevels in bloed o Genezing Radiatie Recap: Iron deficiency or hemorrhage, among other factors, can reduce the oxygen-carrying capacity of blood and result in anemia. Leukemia and multiple myeloma are blood cell cancers. They arise as abnormal cells in the bone marrow multiply in huge numbers.
7.4.4 Mononucleosis: contagious viral infection of lymphocytes • Klierkoorts o Epstein-Barr virus (variant Herpes) o Symptomen Koorts Hoofdpijn Zere keel Moeheid Gezwollen lymfeknopen o Genezing Meestal vanzelf in 4 – 6 weken
7.4.5 blood poisoning : infection of blood plasma • Bloedvergiftiging o Micro-organismen in bloedplasma o Oorzaken Geïnfecteerde wonden Zware branden Urinewegeninfecties Tandprocedures o Genezing Antibiotica 7.4.6 Thrombocytopenia: reduction in platelet number • Trombocytopenie o Te weinig bloedplaatjes in bloed o Oorzaken Virale infectie Bloedarmoede Leukemie Andere bloedstoornissen X-stralen & radiatie Reactie op bepaalde medicijnen o Symptomen Gemakkelijk kneuzen & bloeden Bloedneuzen Bloedingen in mond Bloed in urine Hevige menstruaties o Genezing Onderliggende oorzaak wegnemen Chirurgische verwijdering van milt Recap: Mononucleosis and blood poisoning are types of blood infection. Thrombocytopenia, a disease of too few platelets, is characterized by easy bleeding or bruising.
Hoofdstuk 8: Heart and Blood Vessels 8.1 Blood vessels transport blood • The primary function of blood vessels is to bring blood into close proximity with all living cells. • Thick-walled arteries transport blood to the capillaries at high pressure. • Small arterioles and precapillary sphincters regulate the flow of blood into each capillary. • Thin-walled capillaries are the only vessels that exchange fluids and solutes with the interstitial fluid. • Distensible venules and veins store blood at low pressure and return to the heart. 8.1.1 Arteries transport blood away from the heart - Slagaders o Functie Transport bloed weg van hart Opslag bloed dat erin gepompt is en transport naar haarvaten (zelfs tussen hartslagen) o Structuur Grotere: spieren Vertakkingen 3 lagen rond vaatholte (lumen) • Endothelium o Binnenste laag o Afgeplatte, squamous epitheelcellen • Middelste laag: gladde spieren met elastisch bindweefsel • Dikke laag bindweefsel o Buitenste laag bij grote & medium slagaders o Collageen o Constant onder hoge druk 8.1.2 Arterioles and precapillary sphincters regulate blood - Kleine slagaders & sluitspieren o Functie Regelen bloedtoevoer samentrekken/ontspannen sluitspier o Minder druk o Structuur Geen bindweefsel Dunnere laag spieren Sluitspier: ring van gladde spieren • Contractie vasoconstrictie • Ontspanning vasodilatie Recap: A branching system of thick-walled arteries distributes blood to every area of the body. Arterioles regulate blood flow to local regions, and precapillary sphincters at the ends of arterioles regulate flow into individual capillaries.
8.1.3 Capillaries: where blood exchanges substances with tissues - Haarvaten o Functie Uitwisseling materiaal met interstitiual vocht • Door diffusie (bloeddruk) • Naar interstitiual vocht: vocht gefilterd, samen met zuurstof, voedingsstoffen & ruwe materialen die cel nodig heeft • Naar haarvaten: afvalmateriaal (CO2 en urea) o Structuur Heel dun Enkelvoudige laag squamous epitheelcellen 8.1.4 Lymphatic systems helps maintain blood volume - Lymfensysteem o Functie Bloedvolume constant houden • Overvloedige plasmavocht lymfatische haarvaten Transport van objecten die te groot zijn voor haarvaten Recap: Capillaries consisting of a single layer of cells are the only blood vessels that can exchange materials with the interstitial fluid. The lymphatic system removes excess fluid.
8.1.5 Veins return blood to the heart. - Aders o Functie Transport bloed naar hart Opslag bloed o Werking Skeletspieren duwen bloed naar hart Terugslagkleppen voorkomen dat bloed terugstroomt • Afhankelijk van verschil in bloeddruk aan elke kant Inademen druk in buik verhogen & druk op borstkas verlagen Recap: the thin-walled veins return blood to the heart and serve as a volume reservoir for blood. Return of blood to the heart is assisted by (1) contractions of skeletal muscles, (2) one-way valves inside veins, and (3) pressure changes associated with breathing.
8.2 The heart pumps blood through the vessels • The heart is composed primarily of cardiac muscle. Structurally, it consists of four separate chambers and four one-way valves. Its primary function is to pump blood. • The heart pumps blood simultaneously through two separate circuits: the pulmonary circuit, where blood picks up oxygen and gets rid of carbon dioxide, and the systemic circuit, which supplies the rest of the body’s cells. • The heart contracts and relaxes rhythmically. Contraction is called systole, and relaxation is called diastole. • The coordinated contraction of the heart is produced by as a system of specialized cardiac muscle cells that initiate and distribute electrical impulses throughout the heart muscle. • An electrocardiogram, or ECG, records electrical activity of the heart from the surface of the body. And ECG can be used to diagnose certain cardiac arrhythmias and disorders. 8.2.1 The heart is mostly muscle - Structuur hart o Ingesloten in pericardium Bescherming hart Vasthechting aan structuren Voorkomen dat hart overvol geraakt o Tussen pericardium & hart = pericardiale holte Vocht maakt glijding mogelijk o 3 lagen Buitenste laag: epicardium • Epitheel- & bindweefsel Middelste laag: myocardium • Hartspieren • Laag die samentrekt (75 keer per minuut) • Elektrische signalen tussen cellen Binnenste laag: endocardium • Endotheellaag op bindweefsel Recap: The heart wall consists of three layers. The outer epicardium is a thin layer of epithelial and connective tissue; the middle myocardium consists largely of cardiac muscle and is the layer that contracts. The inner endocardium is a layer of endothelium continuous with the endothelium lining blood vessels.
8.2.2 The heart has four chambers and four valves o 4 kamers & 4 valven 2 bovenste: atrium 2 onderste: ventrikels o Links & rechts gescheiden door septum Recap: The heart is composed of primarily of cardiac muscle. It contains four chambers that pump blood to the lungs and the rest of the body simultaneously. Four one-way valves permit blood flow in one direction only.
8.2.3 The pulmonary circuit provides for gas exchange - Longcircuit & systemisch circuit o Teruggekomen bloed (zonder zuurstof): rechter atrium door klep naar rechter ventrikel door klep naar longen Haarvaten van longen: CO2 afgeven & O2 opnemen Via longaders terug naar hart o Bloed van longen: linkeratrium door klep naar linkerventrikel aorta Door vertakkende aders & kleine slagaders naar haarvaten geeft O2 af & neemt CO2 op Door adertjes & aders naar rechteratrium o Linkerventrikel meest gespierd druk hoger dan die in aorta o Kleppen open & sluiten passief door drukverschillen Atrioventiculaire valven • Functie o Voorkomen dat bloed terugstroomt in atrium • Structuur o Rechter: 3 flexibele flappen o Linker: 2 flexibele flappen o Bindweefsel o Spieren van haarvaten • Sluiting ‘LUB’ Semilunaire valven • Functie o Voorkomen dat bloed terugstroomt in ventrikels • Structuur o 3 flappen • Sluiting ‘Dub’ o Voedingsstoffen & zuurstof nodig Coronaire bloedvaten In myocardium Hartaders boeld van haarvaten hart naar rechteratrium 8.2.4 The systemic circuit serves the rest of the body Recap: the right side of the heart (right atrium and right ventricle) pumps blood to the lungs, where blood is oxygenated and carbon dioxide is removed. The left side of the heart (left atrium and left ventricle) pumps blood to the rest of the body, supplying nutrients and removing wastes.
8.2.5 The cardiac: cycle the heart contracts and relaxes - Hartcyclus o Gecontroleerd door hersenen, maar kan ook zonder o 3 stappen Atrium systole • Beide atria trekken samen • Tijdelijke stop invloei bloed • Hart bijna gevuld • Atrioventriculaire valven open, semilunaire valven gesloten Ventriculaire systole • Beide ventrikels trekken samen • AV-valven sluiten, seminlunaire valven open door druk in ventrikels • Atria ontspannen & vullen opnieuw • Bloed in aorta Diastole • Ventriculaire druk onder druk slagaders semilunaire valven sluiten • AV-valven openen 8.2.6 Heart sounds reflect closing heart valves. Recap: each cardiac cycle is a repetitive sequence of contractions (systole) and relaxation (diastole). The familiar “lub-DUB”of the heart beat is caused by the closing of the heart valves during the cycle.
8.2.7 Cardiac conduction system coordinates contraction. - Elektrische signalen o Oorsprong: cardiac conduction system o 4 stappen Sinotrial node • Verbindingspunt rechteratrium & vena cava • impuls door beide atria • Cardiac pacemaker: begin hartslag Atrioventiculaire node • Tussen atria & ventrikels • Vertraagt impuls alleen atria trekken samen Atrioventiculaire bundel • Vertakt in Purkinje vezels • Impuls naar alle cellen in myocardium van ventrikels ventrikels trekken samen
8.2.8 Electrocardiogram records the heart’s electrical activity - Elektrocardiogram elektrische activiteit o 3 veranderingen P-golf • Impuls in atria QRS-complex • Impuls in septum & 2 ventrikels T-golf • Einde elektrische activiteit in ventrikels o Arryhmia: abnormaliteit hierin o Bv. V-fib Recap: Contraction of the heart is coordinated by modified cardiac muscle cells that initiate and transmit electrical impulses through a specialized conduction system. An electrocardiogram (ECG) is a recording of the heart’s electrical activity taken from the surface of the body.
8.3 Blood exerts pressure against vessel walls. • The heart generates blood pressure, and the arteries store the blood under pressure during diastole. • Systolic and diastolic arterial blood pressures can be measured with a sphygmomanometer. • High blood pressure, called hypertension, is a major risk factor for cardiovascular disease. -
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Definitie o Kracht die bloed uitoefent op wanden van bloedvaten door pompende werking van het hart Meting o Sphygmomanometer o Systolische druk = hoogste druk Ventrikels samentrekken Vanaf je hart hoort pompen o Diastolische druk = laagste druk Ventrikels ontspannen Vanaf je hart niet meer hoort pompen Normale bloeddruk: 12/8
8.3.1 Hypertension: high blood pressure can be dangerous - Hypertensie: te hoge bloeddruk o Blijvende verhoging in bloeddruk (zowel diastole als systole) o “silent killer” cardiovasculaire ziektes o Isolated systolische hypertensie alleen systolische druk verhoogd o 3 stadia Prehypertensie: 120-139/80-89 Hypertensie, stage 1: 140-159/90-99 Hypertensie, stage 2: 160 of meer/ 100 of meer
8.3.2 Hypotension: when blood pressure is too low. - Hypothensie: te lage bloeddruk o Symptomen Duizeligheid Flauwvallen o Oorzaken Plotse verandering in positie Zware branden/ wonden met hevig bloedverlies Recap: blood pressure is the force the blood exerts on the wall of a blood vessel. It is measured as two numbers corresponding to systolic and diastolic pressures. Hypertension (high blood pressure) is a serious risk factor for cardiovascular diseases and other health problems.
8.4 How the cardiovascular system is regulated. • The most important controlled variable in the cardiovascular system is arterial blood pressure. • Arterial blood pressure is monitored by stretch receptors located in certain large arteries. • Cardiac output and the diameters of the arterioles are regulated (controlled) to keep arterial blood pressure relatively constant. • With pressure held constant, local blood flows can be adjusted according to the metabolic needs of the tissues and cells in that area of the body. 8.4.1 Baroreceptors maintain arterial blood pressure - Baroreceptoren o Functie Bloeddruk in kleine slagaders constant houden o Werking Hoge bloeddruk wanden stretchen Baroreceptoren in wand signalen naar cardiovasculair center minder ‘cardiac output’ • Verlaagde hartslag • Verlaagde systolische druk • Vasodilatie Medulla oblongata signalen naar hart via 2 wegen • Sympatische zenuwen: snellere hartslag o Epinephrine (adrenaline) & norepinephrine o Diameter van bloedvaten • Parasympathische zenuwen: tragere hartslag Recap: Homeostatic regulation of the cardiovascular system centers on maintaining a relatively constant arterial blood pressure, making blood available to all cells as needed. Arterial pressure is sensed by barereceptors located in the carotid arteries and aorta.
8.4.2 nerves and hormones adjust cardiac output 8.4.5 Local requirements dictate local blood flows - Locale bloedtoevoer o Verhoogd metabolisme vasodilatie o Bij hevig bloedverlies cruciale organen systeem opheffen
8.4.6 Exercise: increased blood flow and cardiac output - Beweging: verhoogde bloedtoevoer en ‘cardiac output’ o Verhoogd metabolisme productie afvalstoffen + weinig O2 vasodilatie o Weinig verandering in bloeddruk Lichaam anticipeert Recap: The opposing sets of nerves (sympathetic and parasympathetic) and a hormone (epinephrine) adjust cardiac output and arteriole diameters to maintain arterial blood pressure. Local factors regulate blood flow into individual capillaries by altering the diameters of precapillary sphincters. During exercise, blood pressure is maintained by an increase in cardiac output caused primarily by sensory input from muscles and joints.
8.5 Cardiovascular disorders: a major health issue • The heart muscle is always working. Impairment of blood flow to the heart can lead to a sense of pain and tightness in the chest (angina pectoris) and/or permanent damage to heart tissue (myocardial infarction, of heart attack). • Slowly developing, chronic failure of the heart as a pump can lead to excessive interstitial fluid, a condition known as congestive heart failure. • An embolism is the sudden blockage of blood vessel by any object. • Strokes, also called cerebrovascular accidents, can be caused by either embolisms or rupture of blood vessels. The result is damage to a part of the brain when its blood supply is interrupted. 8.5.1 Angina pectoris: Chest pain warns of impaired blood flow - Angina pectoris o Wat? Vernauwde slagaders van hart o Symptomen Pijn & druk op borst Kort van adem Stikkend gevoel o Oorzaken Fysieke inspanningen Emotionele stress Koud weer Zware maaltijden o Genezing Rust & diep ademen Niet negeren! angiografie Medicatie Balloon angioplasty
8.5.2 Heart attack: permanent damage to heart tissue - Hartaanval o Wat? Geen bloedtoevoer naar hart Bepaalde delen van hart sterven myocardial infarction o Symptomen Intense borstpijn Misselijkheid Gevoel van zwaar object op borst o Meest voorkomende oorzaak: ventricular fibriliation o Genezing Directe tussenkomst Soms: coronary artery bypass graft
8.5.3 Congestive heart failure: the heart becomes less efficient - Congestief hartfalen o Wat? Zwakker & minder efficiënt hart Meer vocht dan gewoonlijk in interstitial space o Symptomen Buiten adem na kleine inspanning Gezwollen enkels & benen Gezwollen nekvaten Gewichtstoename (extra vocht) o Oorzaken Leeftijd Hartaanvallen Lekkende hartvalven Hartvalven die niet meer goed opengaan Hypertensie Arrythmias o Genezing Focus op efficiëntie hart verbeteren
8.5.4 Embolism: Blockage of a blood vessel - Embolisme o Wat? Blokkage van bloedvat door materiaal (embolus) o Oorzaken Bloedklonter Cholesterol Kanker Bacteriën Luchtbellen Weefselfragmenten o Genaamd naar plek Longembolisme • Borstpijn • Kort van adem Hersenembolisme o Genezing Onmiddellijke tussenkomst Embolectomy: operatie 8.5.5 Stroke: Damage to blood vessels in the brain - Beroerte o Wat? Schade aan brein door interruptie bloedtoevoer (15% van cardiac output in rust) o Symptomen Zwakheid Verlamming Flauwvallen Moeite met praten Misselijkheid o Genezing Onmiddellijke tussenkomst Recap: Cardiovascular disorders are the number one killer in the U.S. Most disorders are caused either by conditions that result in failure of the heart as a pump of by conditions in which damage to blood vessels restrict flow or ruptures vessels.
8.6 Reducing your risks of cardiovascular disease • Your chances of developing a cardiovascular disorder depend on certain risk factors. Some risk factors a you cannot change, whereas others depend on the choices you make in life. -
Niet roken Cholesterol in de gaten houden Regelmatige beweging Gezond gewicht Hypertensie medische hulp zoeken Diabetes onder controle houden Chronische stress vermijden
Recap: you can reduce your risk of developing cardiovascular disease by not smoking, exercising regularly, watching your weight and cholesterol, and avoid prolonged stress. If you have diabetes and/or hypertension, try to keep these conditions under control.
Hoofdstuk 9: The Immune System and Mechanics of Defense 9.1 Pathogens cause disease • Pathogens include bacteria, viruses, fungi, protozoa, worms, and possibly prions • Bacteria have very little internal structure an are covered by a rigid outer cell wall. • Viruses cannot produce on their own. Viral reproduction requires a living host cell. • Prions are misfolded proteins that replicate by causing a normal protein to misfold. • The danger from a particular pathogen depends on how it is transmitted, how easily it is transmitted, and how damaging the resulting disease is. 9.1.1 Bacteria: single-celled living organisms - Bacteriën o Structuur Geen nucleus & organellen 1 chromosoom met DNA Kleinere, vrije ribosomen Stijve celwand o ATP energie Ontbinding dode dieren & planten Voedingsstoffen van grond & lucht o Niet alle bacteriën zijn pathogeen o Schaden/doden cel o Genezing: antibiotica Recap: Bacteria are single-celled organisms. Like all cells, they draw their energy and raw materials from their environment. Pathogenic bacteria get the materials they need from living cells, damaging or killing the cells in the process.
9.1.2 Viruses: Tiny infectious agents - Virussen o Structuur Zeer klein Genetisch materiaal (RNA/DNA) omringd door proteïnemantel Geen organellen o Kunnen niet zelf reproduceren gebruiken organellen levende cel Toegang tot cel: • Endocytose: proteïnemantel oplossen • Samensmelten • Aanhechten + injectie Cel reproduceren virus ipv eigen metabolische activiteit Verspreiding • ‘uitkiemen’ van celmembraan • Cel ontploft o Genezing Toegang tot cel voorkomen Reproductie virus stoppen
9.1.3 Prions: Infectious proteins - Prionen o Structuur Op abnormale manier opgevouwen versies van eiwitten die in hersenen voorkomen o Werking Andere eiwitten in hersenen ook misvouwen o Genezing? Resistent voor koken, bevriezen & uitdrogen Geen medicatie o Voorbeelden Gekke koeien ziekte Creutzfeld-Jacob + variant Creutzfeld-Jacob (Alzheimer & parkinson?) Recap: A virus consists of a single strand of DNA or RNA surrounded by protein. Viruses use their DNA or RNA to force a living cell to make more copies of the virus. Prions are infectious proteins that cause normal proteins to misfold.
9.1.4 Transmissibility, mode of transmission, and virulence determine health risk - Gezondheidsrisico bepaald door o Overdraagbaarheid o Manier van overdraging o Heftigheid 9.2 The lymphatic system defends the body - Functies o Bloedvolume constant houden o Transport van vet & vetoplosbare vitaminen van spijsverteringsstelsel naar cardiovasculair stelsel o Verdediging tegen infecties • The lymphatic system consists of vessels, lymph nodes, the spleen, the thymus gland, and the tonsils • The lymphatic system helps protect us against disease. • Phagocytic cells in the spleen, lymph nodes, and tonsils engulf and kill microorganisms • The thymus gland secretes hormones that help T lymphocytes mature.
9.2.1 Lymphatic vessels transport lymph - Lymfevaten o Functie Transport materialen die te groot zijn om haarvat binnen te dringen o Structuur 3 dunne lagen 1-richtingsvalven Geholpen door skeletspieren Vocht binnenin: lymfe • WBC • Proteïnen • Vet • Bacteriën & virussen Smelten samen 2 buizen • Borstbuis • Rechter lymfatische buis 9.2.2 Lymph nodes cleanse the lymph - Lymfeknopen o Structuur Orgaan op verloop van lymfevaten Omringd door capsule van bindweefsel met lymfevaten Binnenin • Bindweefsel • WBC o Macrofagen vernietigen vreemde cellen door fagocytose o Lymfocyten activeren andere defensiemechanismen o Functie Verwijderen van micro-organismen, cellulair afval & abnormale cellen Recap: The lymphatic systems helps protect us from disease. As lymph flows through the lymph nodes, macrophages and lymphocytes within the nodes identify microorganisms and remove them.
9.2.3 The spleen cleanses blood - Milt o Functie Controleren kwaliteit RBC (verwijderen beschadigde & oude) Infectie bestrijden o Structuur Boven links in buikholte In capsule van bindweefsel met gladde spiercellen Binnenin • Rode pulp macrofagen o Afbreken micro-organismen o Verwijderen oude & beschadigde RBC & plaatjes • Witte pulp lymfocyten
9.2.4 Thymus gland hormones cause T lymphocytes to mature - Zwezerikklier o Functie 2 hormonen: thymosin & thymopoietin T lymfocyten o Structuur Grootst & actiefst tijdens adolescentie, daarna krimping Tussen borstbeen & luchtpijp 9.2.5 Tonsils protect the throat - Amandelen o Functie Filteren veel micro-organisme o Adenoids: vanachter in neuspassage Recap: The spleen removes damaged red blood cells and foreign cells from blood. The thymus gland secretes hormones that help T lymphocytes mature. Cells in the tonsils gather and remove microorganisms that enter the throat.
9.3 Keeping pathogens out: The first line if defense • Skin is an effective barrier to the entry of microorganisms • Tears, saliva, mucus, and earwax trap organisms and/or wash them away. • Digestive acid in the stomach kills many microorganisms • Vomiting, defecation, and urination physically remove microorganisms after entry. 9.3.1 Skin: An effective deterrent - Huid o Structuur o Hernieuwing o Zure pH o Productie dermicidin door zweetklieren 9.3.2 Impending pathogen entry in areas not covered by skin - Tranen & speeksel o Eiwit lysosoom -
Oorsmeer o Vangt micro-organismen & kleine partikels
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Slijm o
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Vangt micro-organismen
Spijsverterings- & vaginale zuren o Spijsverteringszuur Zuur genoeg om bijna alle pathogenen te doden Uitgezonderd Heliobacter pylori maagzweren o Vaginaal zuur Niet heel zuur
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Braken, urineren & ontlasten o Urine Zuur Constant hernieuwd o Ontlasten: diarree
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Interne bacteriën o Slijmerige membranen rond vagina & spijsverteringsstelsel o Bv. Lactobacillus lager vaginaal pH
Recap: Various mechanisms create an inhospitable environment for pathogenic microorganisms. Skin is a dry outer barrier. Tears, saliva, earwax, and mucus trap them or wash them away. Acidic conditions kill them or inhibit their growth; urination, defecation, and vomiting forcibly expel them; and resident bacteria compete with pathogens for food.
9.4 Nonspecific defenses: The second line of defense • Phagocytes surround and engulf microorganisms and damaged cells • Inflammation has four outward signs: redness, warmth, swelling, and pain. • Natural killer cells kill their targets by releasing damaging chemicals. • Circulating proteins of the complement system either kill microorganisms directly or mark them for destruction. • Interferons are proteins that interfere with viral reproduction. • Fever raises body temperature, creating a hostile environment for some microorganisms. 9.4.1 Phagocytes engulf foreign cells - Fagocyten o Structuur: WBC o Werking: fagocytose Bacterie vangen Verzwelgen Omringen met vesikel Enzymen in lysosoom membraan bacteriën oplossen Exocytose o Neutrofielen eerste ter plaatse o Macrofagen meerdere bacteriën verzwelgen & digesteren + productie meer WBC o Eosinofielen parasieten o Productie van pus abces Recap: Nonspecific defense mechanisms involve a general attack against all foreign and damaged cells. Neutrophils and macrophages engulf and digest bacteria and damaged cells. Eosinophils bombard larger organisms (too large to be engulfed) with digestive enzymes.
9.4.2 Inflammation: redness, warmth, swelling, and pain. - Ontsteking o 4 symptomen Roodheid (rubor) Warmte (calor) Zwelling (tumor) Pijn (dolor) o Werking Chemicaliën beschadigde cellen stimulatie mastcellen productie histamine vasodilatie Vasodilatie WBC in insterstitial vocht • Vreemde organismen & beschadigde cellen aanvallen • Meer bloed roodheid & warmte • Warmte activiteit fagocyten • Meer vocht in weefsel zwelling • Meer zuurstof & voedingsstoffen naar & meer afvalproducten weg 9.4.3 Natural killer cells target tumors and virus-infected cells - Natural killer cellen o Witte bloedcellen o Functie Tumorcellen & cellen geïnfecteerd door virussen vernietigen Herkennen veranderingen in plasmamembranen van kankercellen & door virussen geïnfecteerde cellen o Werking: chemicaliën afbraak membraan target cel o Niet-specifiek 9.4.4 The complement system assists other defense mechanisms - Complementsysteem o 20 plasmaproteïnen die aanvullen of assisteren o Activatie kettingreactie o Verschillende werkingen Samensmelten tot proteïnecomplexen gaten in celwand bacteriën Cellen merken voor vernietiging door fagocyten Mastcellen stimuleren Fagocyten aantrekken 9.4.5 Interferons interfere with viral reproduction - Interferon o Groep eiwitten afgescheiden door cel die door virus geïnfecteerd is o Migreren naar gezonde cellen tussenkomen bij synthese virale proteïnen
9.4.6 Fever raises body temperature - Koorts o Door pyrogenen o Functie Verbetert mogelijkheid om infecties te bestrijden Minder gastvrije omgeving Verhoogde metabolische activiteit Recap: The inflammatory response attracts phagocytes and promotes tissue healing. Natural killes cells release chemicals that disintegrate cell membranes of tumor cells and virus-infected cells. The complement system assist other defense mechanisms, interferons interfere with viral reproduction, and a modest fever enhances our ability to fight infections.
9.5 Specific defense mechanisms: the third line of defense • Cells of the immune system can distinguish foreign or damaged cells from our own healthy cells. • All cells have cell-surface markers called MHC proteins that identify the cells as self • An antigen is a substance that stimulates the immune system and provokes an immune response • B cells produce antibodies against foreign antigens • T cells of several types release chemicals that enhance the immune response and kill foreign cells directly. 9.5.1 The immune system targets antigens - Immuunreactie o Eigenschappen Herkennen & aanvallen specifieke pathogenen of vreemde substanties Geheugen snellere reactie Beschermt hele lichaam o Onderscheid tussen Eigen cellen cell markers: major histocompatibility complex (MHC, uniek voor elke persoon!) • Gezonde cellen • Beschadigde cellen Vreemde cellen -
Antigenen o Elk antigen unieke vorm o Op oppervlak cel geen virussen o Antigen productie antilichamen door immuunsysteem
Recap: An antigen is any substance that provokes an immune response. All cells of an organism have markers called MHC proteins that identify the cells as “self”. Nonself MHC proteins are antigens, and as such they activate the immune system.
9.5.2 Lymphocytes are central to specific defenses - Lymfocyten o WBC o 2 soorten B-cellen • Rijpen in beenmerg • Productie antilichamen T-cellen • Rijpen in zwezerik • Verschillende werkingen o Aanvallen vreemde cellen o Productie proteïnen om andere aspecten immuunreactie te coördineren • Identificeren & doden cellen voor ze kans krijgen om nieuwe bacteriën/virussen vrij te laten in bloed 9.5.3 B cells: Antibody-mediated immunity - B-cellen o Unieke oppervlakreceptoren herkenning specifieke antigenen o Juiste antigen groeien & klonen plasmacellen/memory cellen Plasmacellen antilichamen in lymfevocht & bloedplasma • Antigen-antilichaam-complex: merken antigen • Soms ook inactivatie door te doen samenklonteren Memorycellen 2e keer snellere reactie Recap: Lymphocytes called B cells produce antibodies against specific antigens. When activated by first exposure to an antigen, B cells quickly produce a clone if identical antibody-producing B cells called plasma cells that remain inactivate until the next exposure to the same antigen.
9.5.4 The five classes of antibodies - Antilichamen = Immunoglobulin (Ig) o 5 soorten IgG • Activeren complementsysteem & neutraliseren giffen • Enige die placenta kruisen IgM • Activeren complementsysteem & vreemde cellen doen samenklonteren • Bv. ABO-antilichamen IgA • Neutraliseren pathogenen • Moedermelk IgD • Onduidelijk IgE • Activeren ontstekingsreactie • Allergische reacties
9.5.5 Antibodies’ structure enables them to bind to specific antigens o Structuur 4 polypetidekettingen in Y-vorm • 2 grootste: “heavy chains” • 2 kleinste: “light chains” Constante regio Variabele regio antigen-antilichaam aanhechtingsplaats • Aminozuursequentie bepaalt welk antigen Recap: There are five classes of antibodies (also called immunoglobulins), each with a characterized size, shape, and function. Within each class, a particular antibody fits only one specific antigen.
9.5.6 T cells: cell-mediated immunity - T-cellen o Verschillende oppervlakproteïnen CD4 helper of geheugencellen CD8 cytotocix & supressor cellen o Nood aan antigen-presenting cellen (APC) o Helper-T-cellen Mitose kloon Kloon • Productie cytokinen o Stimuleren T-cellen & macrofagen o Ontwikkeling andere immuuncellen • Aantrekken andere WBC • Activeren B-cellen o Cytotoxic-T-cellen = killer-T-cellen Functie • Aanvallen & vernietigen andere cellen Locatie • Circuleren door lichaam • Migreren naar plaats van infectie of tumor Werking • Afscheiding proteïne perforin gat in target cell water & zout binnenkan • Afscheiding granzyme (giftig eiwit) o Geheugen-T-cellen Bij 2e blootstelling: helper- & cytotoxic-T-cellen Recap: Lymphocytes that mature in the thymus gland become T cells. Helper T cells enhance specific and nonspecific defenses by stimulating other immune cells. Cytotoxic T cells attack abnormal and foreign cells. Memory T cells store information until the next exposure to the same antigen.
9.6 Immune memory creates immunity • Information about an antigen is stored in memory cells after first exposure • The second exposure to the antigen produces a much greater immune response than the first • The rapidity of the second response is the basis of immunity from disease -
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Eerste immuunreactie: o 3 tot 6 dagen na eerste antigen o Piek antilichamen tussen 10 & 12 dagen e 2 immuunreactie o Sneller o Langer o Effectiever o Aantal antilichamen blijft hoger Door mutaties sommige virussen: geen immuniteit
Recap: First exposure to a specific antigen generates a primary immune response. Subsequent exposure to the same antigen elicits a secondary immune response that is faster, longer lasting, and more effective.
9.7 Medical assistance in the war against pathogens • Vaccines immunize the body in advance against a particular disease • Injected antibodies provide temporary immunity and are of some benefit against an existing infection • Monoclonal antibodies are used primarily in medical tests • Antibiotics are effective against bacteria, but not against viruses 9.7.1 Active immunization: An effective weapon against pathogens - Actieve immunizatie o Wat? Activatie immuunsysteem op voorhand o Hoe? vaccin Afkomstig van dode of zwakke pathogenen Nadelen • Tijd, veiligheid & kosten • Immuniteit tegen slechts 1 pathogeen (bv. Griep) • Genezen geen ziekte die je al hebt
9.7.2 Passive immunization can help against existing or anticipated infections - Passieve immunizatie o Wat? Antilichamen van persoon die ziekte al gehad heeft o Hoe? gamma globuline shot Voordelen • Beetje effectief tegen ziekte die je al hebt • Korte-termijn immuniteit Nadelen • Geen lange-termijn immuniteit -
Monoclonal antilichamen o Antilichamen van gekloonde afstammelingen van 1 B-cel o Specifiek voor 1 antigen
Recap: Active immunization with a vaccine (a preparation of weakened or dead pathogens) produces a primary immune response and readies the immune system for a secondary immune response. Administration of prepared antibodies (passive immunization) can be effective against existing infections but does not confer long-term immunity.
9.7.4 Antibiotics combat bacteria - Antibiotica o Functie Bacteriën doden Groei belemmeren o Verschillen tussen menselijke cel & bacteriën Bacteriën dikke celwand DNA bacteriën niet in celkern Ribosomen bacteriën kleiner Proteïne synthese zeer snel o Niet efficiënt tegen virussen o Sommige zeer specifiek, andere ‘broad-spectrum antibiotica’ effectief tegen verschillende bacteria Recap: Monoclonal antibodies are laboratory-produced antibody preparations that are specific tor a single antigen. Most antibiotics kill bacteria by interfering with bacterial protein synthesis or bacterial cell wall synthesis.
9.8 Tissue rejection: A medical challenge • The phenomenon of tissue rejection is a normal consequence of the body’s ability to recognize self from nonself • Immunosuppressive drugs, the ability to test for various antigens, and organ donor matching programs have increased the success rate of organ transplantation in humans -
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Wat? o Aanvallen menselijke cellen die niet als ‘zelf’ gemerkt zijn (bij transplantatie) Probleem o Lichaamscellen héél veel zelf-merkers o Goede match vinden? Oplossing o Testen MHC-antigenen o Minstens 75% match o Immuno-onderdrukkende medicatie vatbaarder voor ziektes
Recap: The major obstacle to organ transplantation is the recipient’s immune response, as cytotoxic T cells usually attack all foreign cells.
9.9 Inappropriate immune system activity causes problems • Allergies occur when the immune system responds excessively to foreign particles that are not otherwise harmful • Autoimmune disorders develop when a person’s immune system attacks the person’s own cells as if they were foreign 9.9.1 Allergies: A hypersensitive immune system - Allergieën o Ongepaste reactie van immuunsysteem op allergeen o IgE-antilichamen o 1e blootstelling B-cellen productie IgE-antilichamen binden aan mastcellen & basofielen e o 2 blootstselling Mastcellen & basofielen histamine afscheiden Ontstekingsreactie o Anafylactische schok Moeite ademen Buikkrampen Instorting met val in bloeddruk Recap: An allergy is an appropriate inflammatory response. Allergens that produce a systemic response can rapidly affect the ability to breathe and maintain blood pressure.
9.9.2 Autoimmune disorders: defective recognition of “self” - Auto-immuunziekten o Productie antilichamen & cytotocix-T-cellen die eigen cellen aanvallen o Oorzaken Nooit blootstelling aan immuunsysteem tijdens foetale ontwikkeling Antilichamen tegen vreemde cel cross-reageren met eigen weefsel o Genezing Echte genezing niet mogelijk Medicijnen die immuunsysteem onderdrukken o Voorbeelden Multiple sclerose: centraal zenuwstelsel Type 1 diabetes mellitus: pancreas Lupus erythematosus • Eigen bindweefsel • 2 soorten o Discoid: gebieden in contact met zonlicht o Systemic: verschillende weefsels & organen • Symptomen o Rode huiduitslag op gezicht & hoofd o Koorts o Vermoeidheid o Gewrichtspijn o Gewichtverlies Rheumatoid arthritis • Ontsteking synovium in gewrichten o Antilichamen tegen proteïne in kraakbeen • Symptomen o Pijn & stijfheid in vingers, polsen, tenen & andere gewrichten o Vernietigt kraakbeen & bot o Misvormingen en verminderd bewegingsbereik • Genezing o Regelmatige beweging & fysische therapie beweging o Medicijnen o Operatie Recap: An autoimmune disorder occurs when the immune system fails to distinguish self from nonself cells and begins to attack the body’s own cells. Examples of autoimmune disorders are lupus erythematosus (inflammation of connective tissue) and rheumatoid arthritis (inflammation of synovial membranes).
Immune deficiency: The special case of AIDS • AIDS is caused by a virus (HIV) • The disease can take years to develop after initial HIV infection, but it is nearly always fatal. • Worldwide, the number of cases of HIV infection and of AIDS is still rising rapidly • The chances of contracting AIDS can be reduced (but never eliminated completely) by practicing “safer” sex. -
AIDS= Acquired Immune Deficiency Syndrome o Door virus HIV (Human Immunodeficiency Virus)
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HIV valt helper-T-cellen aan o Structuur Enkelvoudig RNA-streng Enzymen Geen nucleus & organellen o Toegang tot cel: CD4-receptoren o Retrovirus: replicatie Fuseert met celmembraan Viraal RNA & enzymen in cel Gastcel enkelvoudige DNA-streng & complementaire enkelvoudige DNAstreng
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Overdracht van HIV: lichaamsvocht o Bloed, zaad, borstvoeding & vaginale afscheidingen o Meestal: seksueel contact & geïnfecteerde naalden o Moedermelk: 20% kans o Moeilijk om door te geven, extreem heftig
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AIDS ontwikkelt langzaam o Fase 1 Paar weken – paar jaar na blootstelling Griepachtige symptomen Kleine daling T-cellen, daarna terug normaal HIV-positief = aanwezigheid van antilichamen o
Fase 2 Vernietiging T-helper-cellen Vatbaar voor infecties Volhoudende of terugkomende griepachtige symptomen
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Fase 3 Aantal T-helper-cellen onder 200 per mm³ & infectie of soort kanker geassocieerd met HIV AIDS • Longontsteking • Meningitis • Tuberculose • Encephalitis • Kaposi’s sarcoma • Non-Hodgkins lymphoma Onbehandeld: bijna altijd dodelijk
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AIDS epidemie o Eerste infectie in 1960: andere primaten mensen o Eerst opgemerkt door gelijkheid tussen ‘cases” met rare collectie symptomen o 2/3 HIV-geïnfecteerden: sub-Saharan Afrika o Stijgt sterkst in sub-Saharan Afrika, Zuid- & Zuid-Oost-Azië, Oost-Europa o Sinds 1995: nieuw medicijn daling o Jaarlijks 2 x meer diagnoses dan sterfgevallen
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Risicovolle gedragingen verhogen kansen o Mannen Delen van naalden Sex met andere mannen o Vrouwen Sex met mannen Delen van naalden
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Sex kan veiliger o Onthouding o Aantal seksuele partner klein houden o Seksuele partner met laag-risico gedrag o Geen risico’s nemen met sex o Latex of polyurethane condomen gebruiken o Laat testen
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Nieuwe behandelingen o Werking medicijnen Belemmering replicatie Belemmering protease Belemmering toegang tot cel o Vaccins? HIV muteert snel Te gevaarlijk
Hoofdstuk 10: The Respiratory System: Exchange of Gases 10.1 Respiration takes place throughout the body • Respiration encompasses four processes: breathing, external respiration, internal respiration, and cellular respiration • External respiration occurs in the lungs; internal respiration and cellular respiration take place in the tissues. - 4 processen o Ademen o Externe ademhaling o Interne ademhaling o Cellulaire ademhaling - Speciale functie: productie van geluid 10.2 The respiratory system consists of upper and lower respiratory tracts • The respiratory system includes the air passageways to the lungs and the lungs themselves • Bones and skeletal muscles support the respiratory system and participate in breathing • The upper respiratory tract consists of the nose and pharynx. The upper respiratory tract filters, warms, and humidifies the air we breathe • The lower respiratory tract consist of the larynx, the trachea, the main bronchi, and the lungs • Within the lungs, the bronchi branch many times, becoming smaller airways called bronchioles that end in air filled sacs called alveoli. • The tremendous surface area of the alveoli, coupled with the thinness of the respiratory membrane, facilitates gas exchange with pulmonary capillaries.
10.2.1 The upper respiratory tract filters, warms, and humidifies air - Upper tract o Neus Functie • Doorgang voor ademhaling • Geurreceptoren • Filteren binnenkomende lucht • Bevochtigen & verwarmen binnenkomende lucht • Resonatiekamer toon van stem Structuur • Externe neus • Interne neus= neusholte o Kraakbeen o 2 neusbenen o 2 kamers gescheiden door neustussenschot o Neusharen (filtering) o Epitheelweefsel Bloedvaten (opwarming) Afscheiding slijm (filtering) Cilia slijm naar achterkant neusholte & keelholte o 2 traankanalen o
Keelholte Functie • Verbinding mond & neusholte met larynx • Doorgang eten & lucht Structuur • Neusholte mond • 2 buizen van Eustachius o Verbinding keelholte met middenoor
Recap: The respiratory system is specialized for the exchange of oxygen and carbon dioxide with the air. The upper respiratory tract filters, warms, and humidifies the air.
10.2.2 The lower respiratory tract exchanges gases - Lower tract o Strottenhoofd (larynx) Functie • Productie geluid o Vibratie stembanden o Bewegen tong & tanden • Luchtweg open houden • Eten & lucht in juiste kanalen geleiden Structuur • Epiglottis o Kraakbeen o Klep sluit als we eten/drinken inslikken • Stembanden o Bindweefsel o Omringen glottis (opening naar luchtweg) o Adamsappel (kraakbeen) o
Luchtpijp Structuur • Van larynx linker- & rechterbronchi • C-vormige incomplete ringvormige structuren o Kraakbeen o Houden luchtpijp open o Luchtpijp kan van diameter veranderen Hoestreflex • Plotselinge explosie van lucht uit de longen om vreemd materiaal los te krijgen
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Bronchi Functie • Transport lucht • Filteren lucht • Opwarmen tot lichaamstemperatuur • Verzadigen met water Structuur • Vezelig bindweefsel • Gladde spieren • Kraakbeen (buiten kleinste: bronchiolen) • Epitheelcellen met cilia • Slijm afscheidende cellen
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Longen Ingesloten in 2 lagen dunne epitheelmembranen pleurale membranen • Gescheiden door pleurale holte wrijving verminderen Lobben: 2 in linkerlong, 3 in rechterlong Onafhankelijk van elkaar
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Alveoli Longblaasjes Uiteinden van luchtpijpen Secretie van surfactant door epitheelcellen • Bedekken binnenste alveoli • Oppervlaktespanning verminderen
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Longhaarvaten Functie • Contact van bloed met lucht • alternatieve methode medicatie in bloedbaan
Recap: The larynx maintains an open airway, routes food and air into the appropriate channels, and produces sound. Sound is produced by vibration of the vocal cords as air passes through the glottis. Recap: The trachea, or windpipe, branches into the right and left bronchi, which further subdivide into smaller bronchi and then bronchioles. Like other areas of the respiratory tract, the bronchi and bronchioles filter, warm, and humidify the incoming air before it reaches the gas exchanges structures in lungs. Recap: The lungs are organs containing a branching system of bronchi an bronchioles, blood vessels, and 300 million alveoli and pulmonary capillaries.
10.3 The process of breathing involves a pressure gradient • Inspiration occurs as the lungs expand due to the action of the diaphragm and the intercostals muscles; expiration occurs when these muscles relax • When the lungs expand, the pressure within them falls relative to atmospheric pressure and air rushes in; during expiration, the lungs become smaller and increasing pressure within them forces air out. • During normal breathing, inspiration is active (requiring energy) and expiration is passive • Normally we breathe at about 12 breathes per minute with a tidal volume of 500 ml per breath • Vital capacity is the maximum amount of air a person can exhale after a maximal inhalation
10.3.1 Inspiration brings in air, expiration expels it - Inademen & uitademen o Longen: geen skeletspier kunnen zelf niet samentrekken/ontspannen longholte o 3 stappen Ontspannen status Inademing • Middenrif (diafragma) samentrekken naar beneden • Tussenribspieren samentrekken ribben omhoog & naar buiten • Longen uitzetten o Minder druk op longen o Meer volume longholte • Normale omstandigheden: actief Uitademing • Spiersamentrekkingen stoppen • Normale omstandigheden: passief • Onder stress: actief o Niezen/hoesten: buikspieren plots samentrekken buikdruk verhogen Recap: Inspiration is an active process (requiring energy) that occurs when the diaphragm and intercostal muscles contract. Normally expiration is passive, but it can become active when we forcibly exhale, cough, or sneeze.
10.3.2 Lung volumes and vital capacity measure lung function - Longvolume & vitale capaciteit o Tidal volume (normale ademhaling) = 500 ml 350 ml gasuitwisseling 150 ml = ‘dead space volume’ o Vitale capacitiet = maximumvolume na maximale inademing = 4800 ml Hoeveelheid lucht die we meer inademen = inspiratory reserve volume Hoeveelheid lucht die we meer uitademen = expiratory reserve volume Sommige lucht blijft altijd in longen = residual volume o Meting: spirometer o Toepassing: longziekten opsporen Recap: Although we normally take breaths of about 500 ml (tidal volume), our vital capacity is about 4,800 ml. Some air, called the residual volume, remains in the lungs even at the end of expiration.
10.4 Gas exchange and transport occur passively • The diffusion of a gas is dependent on a partial pressure gradient, which is equivalent to a concentration gradient • External and internal respiration are both processes that occur entirely by diffusion • Nearly all (98%) of the oxygen transported by blood is bound to hemoglobin in red blood cells • Although some carbon dioxide is transported as dissolved CO² or is bound to hemoglobin, most CO² (70%) is converted to bicarbonate and then transported in plasma
10.4.1 Gases diffuse according to their partial pressures - Diffusie o Hoge partiële druk lage partiële druk o Partiële druk = percent gas x atmosfeerdruk (760 mm Hg) 10.4.2 External respiration: The exchange of gases between air and blood - Externe ademhaling o Uitwisseling van gas tussen lucht & bloed o Andere partiële druk van CO2 & O2 1/8 van lucht uitgewisseld per ademhaling: oude lucht in longen o Minder O2 & meer CO2 in haarvaten (deoxygenated bloed) o O2: alveoli haarvaten o CO2: haarvaten alveoli o Aderlijk bloed= bloed zonder O2 10.4.3 Internal respiration: the exchanges of gases with tissue fluids - Interne ademhaling o Uitwisseling van gas met weefselvocht o Cellen halen O2 uit vocht & geven CO2 af in vocht lage partiële druk van O2 & hoge partiële druk van CO2 o O2: haarvaten interstitial vocht o CO2: interstitial vocht haarvaten Recap: In a mixture of gases such as air, each gas exerts a partial pressure. Gases diffuse according to differences in their partial pressures. Diffusion accounts for both external and internal respiration.
10.4.4 Hemoglobin transports most oxygen molecules - Hemoglobine o Transport 98% O2-moleculen O2 niet goed oplosbaar in water Overige 2% bloedplasma o Hb + O2 ↔ HBO2 (oxyhemoglobin) Afhankelijk van partiële druk O2 Neutrale pH & koude temperaturen longen 10.4.5 Most CO² is transported in plasma as bicarbonate - Transport CO2 o Opgelost in bloedplasma (10%) o Binding met hemoglobine (20%) carbaminohemoglobin Hb+CO2 ↔ HbCO2 o Vorm van bicarbonaat CO2 + H2O H2CO3 HCO3 + H+ In rode bloedcellen H+ kan ook aan hemoglobine binden (daarom neutraal pH) Omkeerbaar Recap: Nearly all of the oxygen in blood is bound to hemoglobin in red blood cells. Most carbon dioxide produced in the tissues is transported in blood plasma as bicarbonate.
10.5 The nervous system regulates breathing • A respiratory center in the medulla oblongata of the brain establishes a regular cycle of inhalation and exhalation • Under normal conditions, the rate and depth of breathing as adjusted primarily to maintain homeostasis of arterial blood Pco² • Regulation of respiration by o² comes into play only when the Po² concentration falls by more than 20%, such as in disease states of t high altitude • We can exert some conscious control over breathing 10.5.1 A respiratory center establishes rhythm of breathing - Ademhalingscentrum o Ritme van ademhalen o Medulla oblongate o Elektrische impulsen elke 4 à 5 seconden middenrif & intercostale spieren 10.5.2 Chemical receptors monitor CO², H+, and O² levels - Chemicale receptoren o Functie Homeostase hoeveelheid CO2, H+, O2 o Indirecte werking Verandering in H+-concentratie in cerebrospinaal vocht • Signalen naar medulla oblongata hogere snelheid (als te hoog) • Meer CO2 uitademen Carotid & aortic bodies veranderingen in partiële druk O2 • Medulla oblongata hogere snelheid & diepere ademhaling (als te laag) • Meer O2 inademen • Enkel als verschil van 20% 10.5.3 We can exert some conscious control - Bewuste controle o Cortex verantwoordelijk o Spreken & zingen Recap: The respiratory center in the brain establishes a regular pattern of cyclic breathing. The rate and depth of breathing are then adjusted by regulatory mechanisms that monitor arterial concentrations of CO², H+, and O². Conscious control can modify regulatory control but cannot override it completely.
10.6 Disorders of the respiratory system • Asthma is episodic, spasmodic contractions of the bronchi that impede air flow • Emphysema is a chronic disorder characterized by high resistance to air flow and destruction of alveoli • The lungs are prone to infections because their surface is kept moist and warm in order to facilitate gas exchange. Tuberculosis, is an infectious disease caused by a bacterium. In pneumonia, infected alveoli secrete excess fluid, impairing gas exchange. • Lung disease can be a secondary condition resulting from impairment of another organ, as in congestive heart failure.
10.6.1 Reduced air flow or gas exchange impedes respiratory function - Pleurisy o Ontsteking longmembranen o Pijn tijdens ademen o Symptoom longontsteking -
Infant respiratory distress syndrome o Geen surfactant alveoli inzakken door oppervlaktespanning
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Astma o Wat? Spastische contracties bronchiale spieren Bronchiale zwelling Verhoogde productie slijm Gedeeltelijke sluiting bronchi o Symptomen Hoesten tijdens beweging Kortademigheid Piepen Gevoel van strakheid in borst o Oorzaak Overactief immuunsysteem o Behandelingen Medicijnen • Bronchi te openen • Ontsteking verminderen Oorzaak isoleren & vermijden
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Emfyseem o Wat? Chronische stoornis met schade aan alveoli Destructie bindweefsel luchtwegen minder elastisch o Oorzaken Overerfbaar Roken Lange-termijn blootstelling aan luchtvervuiling
10.6.2 Microorganisms can cause lung disease - Bronchitis o Wat? Ontsteking van bronchi Acuut of chronisch o Symptomen Piepen Zonder adem zitten Aanhoudende hoest met geel-/groenachtige fluimen Koorts o Behandeling Chronisch • Zuurstof • Verwijding bronchi • Verdere test Acuut • Longen bevochtigen • Veel drinken • Antibiotica als bacteriële infectie - Longontsteking o Wat? Ontsteking van longen door infectie (viraal/bacterieel) Alveoli teveel vocht afscheiden gasuitwisseling bemoeilijkt o Symptomen Koorts Rillingen Kortademigheid Bloed met geel-/groenachtige fluimen & soms bloed o Behandeling Afhankelijk van micro-organismen - Tuberculose o Wat? Infectieziekte door Mycobacterium tuberculosis o Besmetting Hoesten & niezen Meestal succesvol bestreden door immuunsysteem 5% in bloedbaan o Symptomen Hoesten (met bloed) Borstpijn Kortademigheid Koorts Nachtzweten Gewichtverlies Verlies van eetlust
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Botulisme o Wat? Vergiftiging door Clostridium Botulinum (bacterie) Blokkeert overdracht zenuwsignalen naar skeletspieren o Symptomen Moeilijk slikken & praten Dubbel zicht Misselijkheid Overgeven
10.6.3 Lung cancer is caused by proliferation of abnormal cells - Longkanker o Wat? Ongecontroleerde groei abnormale cellen Belemmert normale functie: beweging van lucht in longen, gasuitwisseling & bloedtoevoer o Symptomen Chronische hoest Piepen Borstpijn Bloed ophoesten o Oorzaken Roken Radongas Chemicaliën in werkplek 10.6.4 Congestive heart failure impairs lung function - Congestief hartfalen o Belemmert longfunctie hogere bloeddruk in bloedvaten longen o Meer vocht in interstitial vocht & alveoli minder gasuitwisseling 10.6.5 Cystic fibrosis is an inherited disease - Cystic fibrosis o Wat? Productie van dik, plakkerig slijm Belemmert luchttoevoer Plaats voor bacteriegroei o Symptomen Frequente infecties van luchtwegen o Oorzaak Erfelijk Recap: The lungs are prone to damage by environmental pollutants, tobacco smoke, and infections by microorganisms. Cases of both asthma and tuberculosis are on the rise.
Hoofdstuk 13: The Endocrine System 13.1 The endocrine system produces hormones • The endocrine system is a collection of glands that secrete hormones into the blood • Hormones are the chemical messengers secreted by the endocrine system that circulate in the blood and act on specific target cells. •
Wat? o
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Collectie gespecialiseerde cellen, weefsels & klieren die hormonen afscheiden Endocrien: hormonen in interstitial vocht, lymfe & bloed Exocrien: slijm, zweet, tranen & spijsverteringsvocht uit lichaam Hormonen = informatie-units
Eigenschappen o Hormonen bereiken bijna elke levende cel Door bloedvaten o Elk hormoon handelt enkel op specifieke cellen ‘targetcel’ Juiste receptor o Endocriene controle trager dan zenuwstelsel o Endocrien stelsel & zenuwstelsel interageren met elkaar
Recap: Hormones secreted by glands of the endocrine system act only on target cells with appropriate receptors. Hormones reach their targets via the circulatory system, making endocrine system control slower than nervous system control. The two systems frequently interact.
13.2 Hormones are classified as steroid or nonsteroid • Steroid hormones are lipid soluble: they enter the target cell in order to function • Nonsteroid hormones generally are not lipid soluble. The bind to receptors on the outer surface of the cell membrane of the target cell. 13.2.1 Steroid hormones enter target cells •
Steroïde o Structuur Gelijkend op cholesterol Lipide oplosbaar o Werking Diffusie door celmembraan en kernmembraan Hormoonreceptor met nucleus of in cytoplasma Hecht aan DNA formatie messenger RNA synthese proteïnen Trager dan non-steroïde
13.2.2 Nonsteroid hormones bind to receptors on target cell membranes • Non-steroïde hormonen o Structuur Gelijkend op proteïnen Lipide onoplosbaar o Werking Receptoren buitenste oppervlak celmembraan Proteïnemolecules van vorm veranderen verandering in cel Inactieve molecule actief maken second messenger 13.2.3 Hormones participate in negative feedback loops • Negatieve feedback o Controlecenter: endocriene klier (soms hersenen) o Reacties via hormonen o Effectoren: target cellen, weefsels & organen o Niet alle hormonen geregeld via negatieve feedback (bv. Begin puberteit) Recap: Many hormones participate in negative feedback loops that maintain homeostasis of certain controlled variables. Steroid hormones enter the target cell, activate specific genes, and cause the production of new proteins. Nonsteroid hormones bind to a cell membrane receptor that either opens or closes ion channels of activates a second messenger within the cell.
13.3 The hypothalamus and the pituitary gland • The hypothalamus of the brain and the pituitary gland of the endocrine system link the nervous system and endocrine systems. • The posterior lobe secretes two hormones (ADH and oxycotin) that are produced by the hypothalamus • The anterior lobe of the pituitary produces and secretes six hormones (ACTH, TSH, FSH, LH, PRL and GH) the first four stimulate the release of other hormones from other endocrine glands. • Abnormalities of ADH secretion lead to disorders of water balance. • Hypersecretion of growth hormone in a child leads to gigantism; hyposecretion causes dwarfism. In an adult, hypersecretion of growth hormone causes acromegaly. •
Hypothalamus o Structuur Kleine regio in hersenen o Functie Secretie hormonen Monitoring & regeling hormoonsecretie hypofyse Link tussen zenuwstelsel & endocrien stelsel
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Hypofyse o Functie Secretie 8 hormonen o Structuur 2 lobben
13.3.1 The posterior pituitary stores ADH and oxytocin. • Achterste lob o Neuro-endocriene cellen Transport hormonen o ADH Waterbalans Targetcellen in nieren Veranderingen in celdoorlaatbaarheid van water Afgescheiden bij lage concentraties water in bloed o Oxytocin Baarmoedercontracties & melkejectie Targetcellen in borstklieren Neuro-endocriene reflex: stimulus zenuwstelsel verantwoordelijk voor afscheiding Ook in mannen • Seksuele opwinding • Gevoel van seksuele voldoening Recap: ADH acts on the kidneys to regulate water balance. Oxytocin stimulates uterine contractions and milk ejection in pregnant and lactating females, respectively. In both sexes, oxytocin contributes to feelings of sexual satisfaction.
13.3.2 The anterior pituitary produces six key hormones •
Voorste lob o Connectie met hypothalamus = endocrien o Secretie in kleine hoeveelheden rechtstreek in speciale bloedvoorraad o Adrenocorticotropic hormone (ACTH) Targetcells in cortex Stimuleert secretie glucocorticoids • Stress • Glocuse metabolisme Negatieve feedback o Thyroid-stimulation hormone (TSH) Targetcells in schildklier Stimulatie schildklierhormonen o Follicle-stimulation hormone (FSH) Gonadotropin begin puberteit Vrouwen: ontwikkeling ei & afscheiding oestrogeen Mannen: ontwikkeling sperma o Luteinizing hormone (LH) Gonadotropine Vrouwen: ovulatie & afscheiding oestrogeen Mannen: productie testosteron o
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Prolactine (PRL) Ontwikkeling borstkliercellen & productie melk Zwangerschap: geregeld door oestrogeen Na zwangerschap: geregeld door sensorische neurale reflex Geen zwangerschap: onderdrukt door prolactin-inhibiting hormoon Groeihormoon (GH) Stimulatie synthese proteïnen & celdeling Vet als energiebron Effecten duidelijkst in botten & spieren Volwassenen: regulatie metabolisme
Recap: The six hormones produced by the anterior pituitary are ACTH, TSH, FSH, LH, prolactin (PRL), and GH. The release of each hormones is controlled in part by a releasing or inhibiting hormone from the hypothalamus.
13.3.3 Pituitary disorders: Hypersecretion or hyposecretion • Hypersecretie & hyposecretie o Hypersecretie: teveel hormoon ADH diabetes insipidus • Overvloedig urineren • Uitdroging • Dorst • Hoofdpijn • Droge mond Groeihormoon gigantisme Groeihormoon over lange perioden acromegaly • Dikkere botten in gezicht, handen & voeten • Meestal door tumor o Hyposecretie: te weinig hormonen Groeihormoon dwergisme • Behandeling voor adolescentie (daarna groeiplaten vervangen door bot) 13.4 The pancreas secretes glucagon, insulin and somatostatin. • Within the pancreas, clusters of cells called the pancreatic islets produce and secrete three hormones (glucagon, insulin, and somatostatin). • Glucagon raises blood glucose levels, insulin lowers blood glucose levels, and somatostatin appears to inhibit the secretion of glucagon and insulin. • Structuur o Endocriene & exocriene klier o Endocriene cellen = eilandjes van Langerhans • Verschillende cellen verschillende hormonen o Alfa-cellen glucagon Bloedsuiker omhoog Glycogen glucose (in lever) o Beta-cellen insuline Bloedsuiker omlaag Promoveert opname glucose door cellen in lever, spieren & vetweefsel Glucose glycogen (in lever) o Delta-cellen somatostatin Belemmert secretie glucagon & insuline Ook in hypothalamus & spijsverteringsstelsel • Belemmert secretie groeihormoon • Regulatie spijsverteringssapen Recap: Hormones secreted by the pancreas include glucagon, insulin, and somatostatin. Glucagon raises blood glucose levels by increasing production of glucose from glycogen. Insulin lowers glucose levels by facilitating glucose uptake and storage. Somatostatin inhibits the secretion of both glucagon and insulin.
13.5 The adrenal glands comprise the cortex and medulla • The outer zone of the adrenal gland, called the cortex, secretes steroid hormones that affect glucose metabolism (glucocorticoids) and salt balance (mineralocorticoids) • The inner zone of the adrenal gland, called the medulla, is actually a neuroendocrine organ. The adrenal medulla secretes epinephrine into the blood. 13.5.1 The adrenal cortex: Glucocorticoids and mineralocorticoids. • Cortex o Structuur Buitenste laag o Functie Secretie oestrogeen & testosteron Secretie glucocorticoids & mineralocorticoids o Glucocorticoids: cortisol Secretie gestimuleerd door ACTH Bloedglucose levels constant houden Onderdrukken ontstekingsreactie Feedback • Boven setpoint belemmering verdere secretie cortisol & ACTH • Glucoseval systeem opheffen meer cortisol o Meer glucose o Meer aminozuren beschadigd weefsel o Minder kans op ontsteking o Mineralocorticoids: aldosterone Regulatie natrium & kalium Secretie bij • Te weinig natrium • Te veel kalium
13.5.2 The adrenal medulla: Epinephrine and norepinephrine. • Medulla o Productie epinephrine (adrenaline) & norepinephrine Metabolisme Bloeddruk Hartactiviteit o Functie neurotransmitters of hormonen Hormonen: afgescheiden in bloed & targetcells o Opslag in chromaffin cellen gestimuleerd door sympathische zenuwen o Werking Bloedglucose niveau omhoog Hartritme & contractie vermeerderen Ademhalingsritme verhogen Samentrekking/dilatie van bloedvaten Recap: The main secretory products of the adrenal cortex are cortisol and aldosterone. Cortisol raises blood glucose levels and suppresses inflammatory responses, and aldosterone regulates waer balance by promoting sodium reabsorption. The hormones secreted by the adrenal medulla (epinephrine and norepinephrine) contribute to the fight-or-flight response initiated by the sympathetic nervous system.
13.6 Thyroid and parathyroid glands • The thyroid gland produces thyroxine (T4), triiodothyronine (T3), and calcitonin • The four small parathyroid glands produce PTH, which, along with calcitonin, is responsible for the regulation of blood calcium concentration. 13.6.1 The thyroid gland: Thyroxine speeds cellular metabolism • Schildklier o Structuur Onder strottenhoofd voor luchtpijp 2 lobben o Functie Calciumbalans regelen Metabolisme o Thyroxine Activeert genen met code voor eiwitten die helpen bij metabolisme Verhoogt productie & gebruik ATP Negatieve feedback • Te weinig secretie TSH thyroxine secretie o Iodinetekort Nodig voor productie actieve schildklierhormonen Geen thyroxine TSH blijven produceren TSH stimuleert schildklier om te groeien om hormonen te maken o Calcitonin Belemmert activiteit osteoclasten Stimuleert opname calcium door botten Negatieve feedback • Hoge calcium levels calcitonin secretie
13.6.2 Parathyroid hormone (PTH) controls blood calcium levels • Bijschildklier o Structuur 4 kleine klieren Achterste van schildklier o Functie Calciumbalans regelen o Parathyroid hormoon (PTH) Werking • Verwijdert calcium & fosfaat van beenderen • Verhoogt absorptie calcium door spijsverteringsstelsel • Nieren stimuleren om calcium vast te houden & fosfaat uit te scheiden Negatieve feedback Indirect effect door vitamine D • PTH activitatie • Vitamine D absorptie calcium door spijsverteringsstelsel Recap: Production of the thyroid gland hormones (T4 and T3) requires iodine. T3 and T4 speed cellular metabolism and have wide-spread effect on growth in children and basal metabolic rate (BMR) in adults. Calcitonin (from the thyroid) lowers blood calcium levels and PTH (from the parathyroid) raises blood calcium.
13.7 Testes and ovaries produce sex hormones • The primary male sex hormone is testosterone, produced by the testes • The ovaries produce the two female sex hormones, estrogen and progesterone 13.7.1 Testes produce testosterone • Teelballen testosteron o Voor geboorte: ontwikkeling externe genitaliën o Tussen geboorte & puberteit: bijna geen testosteron o Puberteit: LH productie testosteron Ontwikkeling sperma Mannelijke reproductieorganen Libido o Dihydroepiandrosterone (DHEA) bij vrouwen Verbetering vrouwelijke puberale groei Ontwikkeling okselhaar & schaamhaar Libido 13.7.2 Ovaries produce estrogen and progesterone • Eierstokken oestrogeen & progesteron o Puberteit: LH & FSH productie oestrogeen & progesteron o Oestrogeen: ontwikkeling vrouwelijke secundaire geslachtskenmerken & regulatie menstruatiecyclus o Progesteron: regulatie menstruatiecyclus
13.8 Other glands and organs also secrete hormones • The thymus gland produces two hormones (thymosin and thymopoietin) that help lymphocytes mature into T cells • Melatonin from the pineal gland synchronize the body’s daily rhythms to the daily light/dark cycle • The heart secretes atrial natriuretic hormone, the kidneys secrete renin and erythropoietin, and the digestive tract secretes gastrin, secretin, and cholecystokinin 13.8.1 Thymus gland hormones aid the immune system • Zwezerik o Ontwikkeling lymfocyten in T-cellen o Vooral belangrijk in kinderen 13.8.2 The pineal gland secretes melatonin • Pijnappelklier: melatonin o Diep in hersenen o Input van ogen o Secretie melatonin “hormone of darkness” in dag/nacht-ritme o Synchronisatie aan circadiaanse cyclus 13.8.3 Endocrine functions of the heart, the digestive system, and the kidneys • Hart: atrial natriuretic hormone (ANH) o Non-steroïde o Regeling bloeddruk o Afgescheiden door atria •
Spijsverteringsstelsel o Gastrin o Secretin o Cholecystokinin
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Nieren o Erythopoietin: productie RBC in beenmerg o Renin: secretie aldosterone & samentrekken bloedvaten
13.9 Other chemical messengers • Some substances not defined as hormones (because they are not specifically secreted into the bloodstream) nevertheless serve as chemical messengers • Most of these chemical messengers tend to act locally, near their site of secretion. They include histamine, prostaglandins, nitric oxide, and growth factors. • Histamine o Verantwoordelijk voor allergische reactie o Ontstekingen •
Prostaglandins o Locale controle bloedtoevoer o Onstekingsreactie o Bloedklotten bij wonde
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NO o o o
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Regulatie locale bloedtoevoer Peniserectie Samentrekking gladde spieren in spijsverteringsstelsel
Groeifactoren o Tijdstip van celdeling o Richting van celgroei
Recap: Various chemicals messengers (histamine, prostaglandins, nitric oxide, and growth factors) act primarily locally. Among their actions are regulating local blood flows, participating in local defense responses, and regulating growth of specific types of tissue.
13.10 Disorders of the endocrine system • Because the endocrine system controls so many body functions, disruptions can have widespread effects • Hypothyroidism can lead to cretinism (stunted growth and mental retardation) in children and myxedema in adults. Graves’ disease is most common from hyperthyroidism • Insufficient cortisol and aldosterone can cause Addisson’s disease, and hypersecretion of cortisol results in Cushing’s syndrome
13.10.1 Diabetes mellitus: Inadequate control of blood sugar • Diabetes mellitus o Wat? Hoge productie urine met zweetsmaak Krijgen glucose niet in cellen waar het nodig is o Symptomen Uitdroging Dorst Moeheid Frequente infecties Troebel zicht Traaghelende wonden Tintelingen in handen & voeten o Geassocieerde ziektes Cardiovasculaire & neurale aandoeningen Nierfalen Blindheid Schade aan kleine bloedvaten amputatie o 2 types Type 1 (insuline-afhankelijke) • Falen van pancreas: te weinig insuline • Oorzaak: virus beta-cellen van pancreas aanvallen Type 2 • Insuline resistentie • Geen reactie op insuline door cellen
13.10.2 Hypothyroidism: underactive thyroid gland • Hypothyroidism o Wat? Onderactiviteit schildklier o Symptomen Trage lichaamsgroei Veranderde hersenontwikkeling Verlaatte puberteit o Oorzaak van cretinisme bij kinderen Mentale achterstand Dwerggroei o Oorzaak van myxedema bij volwassenen Onderhuids edema (zwelling) Slaperigheid Gewichtstoename Lage lichaamstemperatuur Lage BMR (metabolische activiteit)
13.10.3 Hyperthyroidism: overactive thyroid gland • Hyperthyroidism o Wat? Overactiviteit schildklier o Symptomen Hyperactiviteit Zenuwachtigheid Opwinding Gewichtsverlies o Bv. Graves’ disease Auto-immuunziekte: te veel thyroxine Uitpuilende ogen 13.10.4 Addison’s disease: too little cortisol and aldosterone • Addison’s disease o Wat? Falen van bijnier te weinig cortisol & aldosterone o Symptomen Moeheid Zwakheid Buikpijn Gewichtsverlies Bronzen huidskleur
13.10.5 Cushing’s syndrome: too much cortisol • Cushing’s syndroom o Wat? Te veel cortisol productie van glucose & te veel water & zout vasthouden Glucoseconcentratie in bloed stijgt Spiermassa vermindert o Symptomen Spierzwakte Moeheid Edema Hoge bloeddruk
Hoofdstuk 14: The Digestive System and Nutrition 14.1 The digestive system brings nutrients into the body • The digestive system consists of the gastronomical (GI) tract and four accessory organs: the salivary glands, liver, gallbladder, and pancreas • The five basic processes of the digestive system are mobility, secretion, digestion, absorption, and excretion • Two types of motility in the GI tract are peristalsis, which propels foods forward, and segmentation, which mixes the contents • Wat? o Alle organen die dezelfde functie delen: voedingsstoffen in het lichaam brengen o Gastrointenstinal (GI) tract = holle buis Ruimte = lumen o 4 bijkomende organen Speekselklieren Lever Galblaas Pancreas 14.1.1 The walls if the GI tract are composed of four layers • GI tract: structuur o 4 lagen Binnenste laag = mucosa • Door mucosa om bloed binnen te gaan Submucosa • Bindweefsel met bloedvaten, lymfevaten & zenuwen Muscularis • Verantwoordelijk voor beweging • Gladde spieren • Circulaire manier rond lumen Buitenste laag = serosa • Dun bindweefsel • Omringt & beschermt 3 andere lagen • Aanhechting aan lichaam o Organen gescheiden door sluitspieren Recap: The digestive system consists of organs and accessory organs that share the function of bringing nutrients into the body. The wall of the GI tract consists of four tissues layers: the mucosa, the submucosa, the muscularis, and the serosa.
14.1.2 Five basic processes accomplished digestive system function • basisprocessen o Mechanische verwerking & beweging Kauwen kleinere stukken 2 soorten beweging o Secretie Vocht, spijsverteringseiwitten, zuur, alkali, gal & slijm in GI tract Hormonen in bloedbaan o Digestie Mechanisch & chemisch kleinere stukken Voedingsmoleculen o Absorptie Voedingsmoleculen door mucosa in bloed/lymfe o Eliminatie Onverteerd afval anus
14.1.3 Two types of motility aid digestive processes • 2 soorten beweging helpen proces o Peristalsis Knijpbeweging van buisvormig orgaan Vooral in slokdarm o Segmentatie Kleine secties gladde spieren trekken samen & ontspannen mixen Voedsel tegen mucosa geduwd voedingsstoffen Vooral in dunne darm
14.2 the mouth processes food for swallowing • The 32 teeth of adults include incisors, canines, premolars, and molars. Teeth cut, tear grind, and crush food. • Saliva moistens food, begins the digestion of starch, and helps to protect against bacteria. 14.2.1 Teeth bite and chew food • Tanden o Functie Snijtanden snijden eten Hoektanden verscheuren eten Kiezen malen o Structuur Kinderen: 20 tanden Volwassenen: 32 tanden Kroon boven tandvlees • Email (calcium & fosfaat) • Tandbeen (dentine) • Tandpulp o Bloedvaten o Zenuwen Wortel onder tandvlees ‘goede bacteriën’ zuur door metabolische activiteit gaatjes 14.2.2 The tongue positions and tastes food • Tong o Functie Eten positioneren & proeven Spraak o Structuur Skeletspier Slijmvlies 14.2.3 Saliva begins the process of digestion • Speeksel o 3 speekselklieren Parotid achterkant kaak Submandilar & sublingual onder onderste kaak & tong o 4 ingrediënten Mucin voedsel bijeenblijft Salivary amylase vertering carbohydraten Bicarbonate (HCO3-) pH tussen 6,5 & 7,5 Lysozyme belemmert bacteriële groei Recap: The four kinds of teeth (molars, premolars, canines, and incisors) mechanically digest chunks of food. Salivary glands secrete saliva, which moistens food, begins the chemical digestion of carbohydrates, maintains the PH of the mouth, and protects the teeth against bacteria.
14.3 The pharynx and esophagus deliver food to the stomach • Swallowing is a reflex that is initiated by voluntary movements of the tongue. Once started, swallowing is voluntary. • The sole function of the esophagus is to get food from the mouth to the stomach • The lower esophageal sphincter prevents reflux of stomach contents. • Keel o Tong & kaak eten in keel (vrijwillig) o Slikreflex (onvrijwillig) Strotklepje sluiten geen voedsel in luchtwegen Tong duwt eten voorbij strotklepje in slokdarm •
Slokdarm o Skeletspieren & gladde spieren o Productie slijm transport vergemakkelijken o Peristalsis o Sluitspier geen reflux Malfunctie: acid reflux Kan indicatie zijn van hiatal hernia (maag naar boven komt)
Recap: swallowing begins with voluntary movements of the tongue; the presence of food initiates an involuntary swallowing reflex. Peristalsis and gravity transfer food trough the esophagus to the stomach.
14.4 The stomach stores food, digests protein, and regulates delivery • The stomach stores ingested food until it can be delivered to the small intestine. • Glands in the mucosa of the stomach secrete gastric juice into the lumen, beginning the process of protein digestion • Peristalsis of the stomach mixes the food and pushes it toward the small intestine • Functies o Voedselopslag Capiciteit van 1-3 liter als we eten o Vertering Proteïnen zuur & enzymen Zuur doodt meeste bacteriën o Regulatie van levering Aan dunne darm
14.4.1 Gastric juice breaks down proteins • Maagsap o Kleine openingen naar maagklieren Secretie HCl Secretie slijm (maagwand beschermen tegen zure inhoud) Secretie pepsinogen (enzyme pepsin in zure omgeving) o pH = 2 o 1-2 liter per dag o Proteïnen & peptiden afgebroken tot aminzuren o Spijsbrij = deels verteerd voedsel & maagsappen naar dunne darm: geregeld door pylorische sluitspier Recap: the stomach stores food, digests it, and regulates its delivery to the small intestine. Gastric juice dissolve connective tissue, large proteins, and peptides in food.
14.4.2 Stomach contractions mix food and push it forward • Maagcontracties: peristalsis o Start aan onderste sluitspier van slokdarm pylorische sluitspier o Elke 15-25 seconden o Elke contractie: eetlepel spijsbrij in dunne darm o 2-6 uur eer maag leeg is o Zuur spijsbrij secretie hormonen vertragen peristalsis dunne darm voedingsstoffen absorberen Recap: the presence of food stretches the stomach and increases peristalsis. Peristaltic contractions mix the chyme and push it gradually in the small intestine.
14.5 The small intestine digests food and absorbs nutrients and water • Digestion occurs primarily in the first part of the small intestine, called the duodenum • The jejunum and ileum of the small intestine absorbs most of the products of digestion • The smallest intestine has a very large surface area because of its many folds, villi, and microvilli • 2 functies o Vertering Carbohydraten & lipiden Zuur neutraliseren Spijsverteringsenzymen van darm & pancreas toevoegen o Absorptie Afgebroken tot enkelvoudige aminozuren, monosacchariden, vette zuren & glycerol Door mucosa in bloed
14.5.1 The small intestine has a large surface area for absorption • Dunne darm o Structuur: 3 regio’s Duodenum (twaalfvingerige darm) • Meeste vertering Jejunum (nuchtere darm) & kronkeldarm (ileum) • Absorptie • Villi & microvilli o Groter oppervlak o Bloedvaten & kleine lymfevaten Recap: The small intestine has two major functions: a. digesting proteins, carbohydrates and lipids; and b. absorbing approximately 90% of the nutrients and water we consume. Projections called villi in the mucosa increase the small intestine’s surface area for absorption.
14.6 Accessory organs aid digestion and absorption • The pancreas secretes fluid containing bicarbonate and digestive enzymes into the small intestine • The liver produces bile and participates in homeostasis in a variety of ways • All of the venous blood from the GI tract is routed directly to the liver • The gallbladder stores bile from the liver and concentrates it by removal of most of the water 14.6.1 The pancreas secretes enzymes and NaHCO3 • Pancreas o Spijsverteringseiwitten Protease vertering proteïnen Pancreatic amylase vertering carbohydraten Lipase vertering lipiden o NaHCO3 Neutraliseren maagzuur Recap: The pancreas assists digestion by producing (1) digestive enzymes and (2) sodium bicarbonate to neutralize stomach acid and make enzymes more effective
14.6.2 The liver produces bile and performs many other functions • Lever o Locatie Boven rechts in buikholte o Functie Productie gal spijsvertering Opslag vetoplosbare vitaminen & ijzer Opslag & conversie glycogen Making plasma-proteïnen Synthese & opslag sommige lipiden Inactivatie chemicaliën Converteren ammonia urea Vernietigen oude RBC
o
Werking Gal afbreken in kleinere stukken verteerd door lipase Porta hepatis • Voert bloed met voedingsstoffen van andere spijsverteringsorganen naar lever
14.6.3 The gallbladder stores bile until needed • Galblaas o Opslag gal o Geconcentreerder water eruit gehaald Recap: Bile is produced by the liver and stored in the gallbladder until after a meal. The liver also produced plasma proteins; inactivates toxic chemicals; destroys old red blood cells; stores vitamins, iron and certain products of metabolism; and performs other functions important for homeostasis.
14.7 The large intestine absorbs nutrients and eliminates wastes • The large intestine absorbs most remaining nutrients and water, and vitamin H produced by bacteria. It also stored wastes • Defecation is generally controlled by a neural reflex, but it can be overridden by conscious control • Functie o Opslag afvalmateriaal o Absorptie water & voedingsstoffen • Structuur o Blinde darm = appendix o 4 colons (zie figuur 14.12) o Bacteriën bruikbare bijproducten (bv. Vitamine K) & gas o Interne anale sluitspier neurale reflex (onvrijwillig) o Externe anale sluitspier vrijwillig Recap: The large intestine absorbs the last of the water, ions, and some nutrients and stores feces until defecation occurs
14.8 How nutrients are absorbed. • Amino acids and simple sugars are actively transported into the mucosal cells that line the small and large intestines • The products of fat digestion enter the mucosal cells by diffusion, then re-form into triglycerides. Triglycerides are coated with protein and move into lymph vessels for transport to the blood • Water is absorbed by osmosis • Vitamins and minerals follow a variety of specific pathways
14.8.1 Proteins and carbohydrates are absorbed by active transport • Proteïnen & carbohydraten o Enzymen: proteïnen aminozuren mucosa (diffusie) o Carbohydraten polysacchariden disacchariden monosacchariden actief transport Recap: Proteins and carbohydrates are absorbed from the lumen of the small intestine by active transport processes, then move by facilitated diffusion into capillaries.
14.8.2 Lipids are broken down, then reassembled • Lipiden o Lipiden vette zuren & monoglyceriden o Non-polair oplossen in micellen absorptie in cel o In cel triglyceriden + proteïnen chylomicronen exocytose lymfevaten 14.8.3 Water is absorbed by osmosis • Water o Osmose Lage hoge concentratie o Dunne darm: geen limiet op absorptie o Dikke darm: limiet diarree o Constipatie: teveel water geabsorbeerd 14.8.4 Vitamins and minerals follow a variety of paths • Vitaminen & mineralen o Vetoplosbare vitaminen Oplossen in micellen Diffusie o Wateroplosbare vitaminen Actief transport Diffusie door kanalen/poriën o Mineralen Actief transport Diffusie door kanalen, poriën of transportproteïnen Recap: The components of lipid digestion are transported to the mucosa in micelles, diffuse into the cell, and recombine into lipids within the cell. Then they are coated with protein to become chylomicrons that enter the lymph. The digestive system also absorbs water, vitamins, minerals, and digestive secretion.
14.9 Endocrine and nervous systems regulate digestion • The volume and content of food play a large part in regulating digestive processes • Stretching of the stomach increases stomach peristalsis and the secretion of gastric juice • Stretching of the small intestine inhibits gastric motility, increases intestinal segmentation, and cases the secretion of two digestive enzymes, secretin and cholecysokinin • Acid in the small intestine triggers the secretion of pancreatic juice containing bicarbonate
14.9.1 Regulation depends on volume and content of food • Regulatie = veranderen beweging & secretie organen om alles zo efficiënt mogelijk te laten verlopen o Meestal: homeostase o Spijsvertering: snelle, efficiënte vertering and absorptie interne omgeving verandert in paar uren •
Afhankelijk van volume & inhoud van voedsel o Strekken van maag + aanwezigheid proteïnen maag: secretie gastrin maagsappen o Zuur in spijsbrij twaalfvingerige darm: secretie secretin pancreas: water & bicarbonaat (neutralisatie) o Vet & proteïnen twaalfvingerige darm: secretie cholecystokin (CCK) pancreas: meer spijsverteringsenzymen o CCK + strekken twaalfvingerige darm galblaas samentrekken en gal vrijlaten
Recap: The endocrine and nervous systems regulate digestion based on content and volume of food. Regulatory mechanisms include neural reflexes involving organ stretching and release of the hormones gastrin, secretin, and cholecystokinin.
14.9.2 Nutrients are used or stored until needed • Voedingsstoffen worden gebruikt of opgeslagen o Regulatie door pancreas & lever Teveel: opslag in andere vorm lichaamsgewicht toenemen Te weinig: conversie gewicht verliezen Recap: lipids, carbohydrates, and amino acids can all be converted to storage forms of lipid or carbohydrates. They can be recreated from stored forms according to the body’s needs at the moment
14.10 Nutrition: you are what you eat • Good nutrition requires a variety of foods weighted toward fruits, vegetables, and wholegrains products • The human body needs certain nutritional components that it cannot make, including a few fatty acids, eight amino acids, 13 vitamins and all essential minerals 14.10.1 MyPyramid plan offers a personalized approach • MyPiramid Recap: Good nutrition includes maintaining a healthy weight while consuming a variety of foods. Eat plenty of fruit, vegetables, and whole grains; cut back on saturated fat; and use sugar salt and alcohol in moderation.
14.10.2 Carbohydrates: A major energy source • Carbohydraten o Basisbron energie o 45-65% van calorieën o Simpel of complex beter dan refined suiker o Trage suikers Recap: carbohydrates are a good source of energy. Natural sugars and complex carbohydrates are the best sources.
14.10.3 Lipids: Essential cell components and energy sources • Lipiden o Fosfolipiden & cholesterol = celmembraan o Verzadigde versus onverzadigde (gezonder) vetten o Transvetten Commerciële doeleinden Doen LDL cholesterol toenemen o Meeste vetzuren kan lichaam zelf maken, uitzondering: essentiële vetzuren Bv. Lineolic & linolenic Via voedsel o 20-35% calorieën Recap: Saturated fats are found mostly in meat and dairy products, and trans fats are found in many snacks and processed foods. Unsaturated fats, which include plant and fish oils, are a healthier choice. Some essential fatty acids must be consumed to meet the body’s nutritional requirements.
14.10.4 Complete proteins contain every amino acid • Proteïnen o Functie Enzymen voor metabolisme Receptor & transport moleculen Spiervezels Soms: hormonen o Compleet proteïne = 20 aminozuren 12 kan lichaam zelf maken • In kinderen: histidine & arginine via voedsel wegens snelle groei 8 andere via voedsel o 15% calorieën Recap: The body needs 20 amino acids but cannot synthesize eight of them, called essential amino acids. Complete proteins contain all 20 amino acids. Most animal proteins are complete but most plant proteins are incomplete.
14.10.5 Vitamins are essential for normal function • Vitaminen o 13 chemicaliën o Slechts weinigen gemaakt door lichaam Synthese vitamine D door huid Bacteriën vitamine K, B6 & biotin o Rest via voedsel o Vetoplosbare blijven voor jaren in lichaam o Wateroplosbare slechts kort opgeslagen 14.10.6 Minerals: elements essential for body processes • Mineralen o Ionen in bloedplasma & celcytoplasma o 21 mineralen essentiëel 14.10.7 Fiber benefits the colon • Vezel o Onverteerbaar o Maakt uitwerpselen lijvig o Weinig vezels Constipatie Aambeien • Gezwollen aders in anus • Oorzaak vaak persen bij ontlasting Diverticulosis Groter risico op darmkanker o 20-35 gram vezels / dag Recap: All minerals and nearly all vitamins must be obtained from food. For most healthy people, a balanced diet, including adequate fiber, is the best way to achieve the RDA.
14.11 Weight control: energy consumed versus energy spent • The basal metabolic rate (BMR) represents the daily energy needs of the body for all essential activities except physical activity • Fat contains over twice as many calories per gram as carbohydrate or protein • A person must use 3500 calories more than he or she ingests to lose a pound of body fat • Energie nodig voor metabolische activiteit o 1 calorie = hoeveel energie om 1 gram water 1° C op te warmen o 1 C = 1000 calorieën
14.11.1 BMR: determining how many calories we need • BMR: basal metabolic rate o Energie die lichaam nodig heeft voor essentiële activiteiten, bv. Ademen o Factoren Geslacht & lichaamscompositie: spierweefsel meer nodig Leeftijd: vermindert Gezondheid Stress: omhoog Voedselopname: omhoog Genen o 2/3 van dagelijks energieverbruik 14.11.2 Energy balance and body weight • Energiebalans & lichaamsgewicht o Meer calorieën eten dan we nodig hebben gewicht toenemen o Vetten 9 calorieën per gram, carbohydraten & proteïnen 4 calorieën per gram Recap: weight control involves balancing energy consumed in food against energy spent. Calculating your BMR helps you estimate how many calories you need each day.
14.11.3 Physical activity: an efficient way to use calories • Fysieke activiteit o Meer gewicht meer calorieën verbruiken voor dezelfde activiteit o Voordelen Verbetert cardiovasculaire gezondheid Maakt beenderen sterker Versterkt spieren Algemeen gevoel van welzijn 14.11.4 Healthy weight improves overall health • Gezond gewicht goede gezondheid o Correlatie tussen obesitas & Hartziekten Diabetes Kanker Artritis o Body Mass Index (BMI) Recap: Increasing physical activity is an efficient way to increase calories expenditure. The best strategy for losing weight combines a healthful diet with moderate regular exercise.
14.12 Disorders of the digestive system • Lactose intolerance is caused by the lack of the enzyme (lactase) that normally digests lactose • Hepatitis, or inflammation of the liver, can be caused by several different viruses • Starvation is the most common form of malnutrition in the world. However, the incidence of obesity is rising in the U.S. and other industrialized nations
14.12.1 Disorders of the GI tract • Voedselvergiftiging o Wat? Eten besmet met bacteriën of hun giftige producten o Symptomen Diarree Overgeven •
Voedselallergieën o Diarree o Braken o Allergische reactie over hele lichaam
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Lactose-intolerantie o Wat? Enzyme lactase vertering melk In volwassen: langzaam verdwijnen o Symptomen (na melkproducten te consumeren) Diarree Winderigheid Zwelling Buikkrampen
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Diverticulose o Wat? Aanwezigheid divertikels (zakvormige uitstulping van hol orgaan) Divertikels kunnen ontsteken o Oorzaak Dieet met weinig vezels kleinere uitwerpselen sterkere contracties zwakke plaatsen naar buiten geduwd
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Darmpoliepen o Wat? Uitpuiling mucosa darmwand o Behandeling Operatie (soms begin kanker) Colonoscopy
14.12.2 Disorders of the accessory organs • Hepatitis o Wat? Ontsteking van de lever door virussen of giftige substanties o 3 soorten Hepitatis A • Overdracht via eten of water • Korte ziekte • Vaccin Hepitatis B • Overdracht via bloed & lichaamsvocht • Onbehandeld leverfalen • Symptomen o Geelzucht o Misselijkheid o Moeheid o Buikpijn o Atritis • Vaccin Hepitatis C • Overdracht via bloed • Onbehandeld chronische hepatitis, cirrose, lever kanker •
Galstenen o Wat? o
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Teveel aan cholestrol uit geconcentreerde gal + calcium & galzout harde kristallen Galtoevoer blokkeren buikpijn na maaltijd Schade aan tandvlees Vermindert email Geassocieerd met depressie & angstgevoelens
14.12.3 Malnutrition: too many or too few nutrients • Malnutritie o Wat? Ongebalanceerd dieet o Oorzaken Overnutritie obesitas Ondernutritie o Gevolgen Bv. Vitamine A oogschade & nachtblindheid
14.12.4 Obesity: a worldwide epidemic? • Obesitas o Oorzaken Omgevingsfactoren Genetische factoren Recap: Disorders of the GI tract and accessory organs include lactose intolerance, diverticulosis, colon polyps, gallstones and hepatitis. Malnutrition can be caused by over- or undernutrition. Whereas starvation is the leading cause of malnutrition in underdeveloped countries, obesity is increasing in industrialized nations.
14.13 Eating disorders: Anorexia nervosa and bulimia • Two serious eating disorders are anorexia nervosa, in which the person diets excessively or stops eating entirely, and bulimia, a binge-and-purge condition in which the person eats and deliberately vomits or takes other steps to minimize caloric intake • The most effective treatments are multidisciplinary, addressing medical, psychiatric, dental, psychological and nutritional needs • Anorexia nervosa o Wat? Overvloedig dieet of niet meer eten o Symptomen Wegen minder dan 85% van normale gewicht Angst om bij te komen Verstoorde perceptie over hun gewicht Stoppen van menstruele cyclus Slapeloosheid Haarverlies Vermoeidheid Stemmingswisselingen Verliezen van beenmassa Osteoporosis o Geassocieerd met depressie & angstgevoelens •
Boulimie o Wat? Eetbuien gevolg door manieren om van calorieën af te geraken o Symptomen Eetbuiten Ongepaste manieren om te vermageren Veel bezig met gewicht Zweren Chronisch brandend maagzuur Rectale bloedingen Zwelling speekselklieren
Hoofdstuk 15: The Urinary System 15.1 The urinary system contributes to homeostasis • The kidneys, the lungs, the liver, and the skin all participate in the maintenance of homeostasis • The kidneys are the primary regulators of water balance and most excess solutes, especially inorganic ions and urea 15.1.1 The kidneys regulate water levels • Waterniveau o Evenveel opnemen als afscheiden 15.1.2 The kidneys regulate nitrogenous wastes and other solutes • Stikstofhoudende afvalstoffen & andere opgeloste stoffen o Ammoniak urea (door lever) o Na+ & Cl- volume extracellulair vocht (bv. Bloed) o Ka+ elektrische lading tussen membranen o Ca2+ zenuw- & spieractiviteit o H+ zuur-base balans Recap: the urinary system maintains a constant internal environment by regulating water balance and body levels of nitrogenous wastes, ions, and other substances. It filters metabolic wastes from the blood and excretes them in urine. The major nitrogenous waste product is urea.
15.2 Organs of the urinary system • The urinary system consists of those organs that produce, transport, store and excrete urine. The urinary system includes the kidneys, the ureters, the bladder, and the urethra. • Functions of the kidneys include regulation of the volume and composition of body fluids, excretion of wastes, regulation of blood pressure, regulation of the production of red blood cells, and the activation of vitamin D. 15.2.1 Kidneys: the principal urinary organs • Nieren o Renale slagader & renale adel connectie aorta & inferior vena cava o Dicht weefsel medulla + buitenste laag: cortex Nefronen collecting duct o Binnenste: renal pelvis
15.2.2 Ureters transport urine to the bladder • Urineleiders o Transport urine naar blaas o Contracties gladde spieren
15.2.3 Urinary bladder stores urine • Urineblaas o Opslag urine o 3 lagen gladde spieren o Binnenkant: epitheelcellen 15.2.4 Urethra carries urine from the body • Urinekanaal o Transport urine naar buiten o Gespierde buis o 2 sluitkleppen: intern & extern Recap: organs of the urinary systems include the kidneys, ureters, bladder, and urethra. The kidneys are the principal urinary organs, although they have several homeostatic functions as well. The ureters transport urine to the bladder, where it is sorted until carried by the urethra to the body’s external opening.
15.3 Nephrons produce urine • The functional unit of the kidneys is the nephron. Each nephron consists of a tubular component and the blood vessels that supply it. • The tubular components of a nephron are the glomerular capsule, proximal tubule, loop of Henle, distal tubule, and collecting duct. The collecting duct is shared by many nephrons. • A tuft of capillaries called the glomerulus is enclosed within each glomerular capsule. Peritubular capillaries supply proximal and distal tubules, and vasa recta supply loops of Henle and collecting ducts. • Structuur o Dunne holle buis Glomerular capsule (weefsel) Glomerus (omringt bloedvaten) o Epitheelcellen o Bloedvaten 15.3.1 The tubule filters fluid and reabsorbs substances • Tubule: buis + epitheelcellen o 4 regio’s Proximal tubule: glomerular capsule renal medulla Loop of Henle: medula glomerular capsule • Afdalende limb • Stijgende limb Distal tube Collecting duct o Begin urineformatie Plasmavocht gefilterd uit haarvaten In ruimte tussen 2 lagen glomerular capsule
15.3.2 Special blood vessels supply the tubule • Speciale bloedvaten o Elke nefron: afferente kleine slagader o Netwerk van haarvaten Efferente kleine slagader transport gefilterd bloed Peritubulaire haarvaten (rond proximal & distal tube) verwijderen ionen, water & voedingsstoffen (reabsorbatie) Vasa recta toevoer naar loop of Henle & collecting duct Recap: A nephron is the functional unit of a kidney. A nephron tubule consists of a glomerular capsule, where fluid is filtered, and four regions in which the filtrate is modified before it becomes urine: proximal tubule, loop of Henle, distal tubule, and collecting duct. Blood flows to the glomerulus via the renal artery and afferent arterioles. Peritubular capillaries carry the blood to the proximal and distal tubules, and vasa recta supply the loops of Henle and collecting ducts.
15.4 formation of urine: filtration, reabsorption, and secretion • The formation of urine involves three processes: glomerular filtration, tubular reabsorption, and tubular secretion. • Approximately 180 liters per day of protein-free plasma fluid is filtered across the glomerulus and into the glomerular space. Filtration is driven by high blood in the glomerular capillaries. • Ninety-nine percent of all filtered water and salt and all of the filtered bicarbonate, glucose, and amino acdis and reabsorbed in tubular reabsorption. The active transport of sodium provides the driving force of the reabsorption of nearly all other substances. • Tubular secretion is a minor process relative to reabsorption but is critical for the regulation of acid-base balance and for the removal of certain toxic wastes. 15.4.1 Glomerular filtration filters fluid from capillaries • Glomerular filtratie o Proteïne-vrij plasmavocht van glomerular haarvaten naar glomerular ruimte o 2 celtypes Epitheelcellen: prodocyten Haarvatcellen o Zeer selectief o Gefilterde vocht = glomerular filtraat Geen grote protëinen Geen bloedcellen o Gedreven door bloeddruk 2 keer zo hoog dan in andere haarvaten o 2 manier om snelheid te regelen In rust: drukgevoelige cellen in kleine slagaders & stromingsgevoelige cellen in tubule afscheiding chemicaliën diameter afferente kleine slagaders In stress: sympatische deel van autonoom zenuwstelsel efferente & afferente kleine slagaders samentrekken Recap: glomerular filtration separates plasma fluid and small solutes from larger proteins and blood cells. High blood pressure in the glomerular capillaries drives this process.
15.4.2 Tubular reabsorption returns filterd water and solutes to blood • Tubulaire reabsorptie o Reabsorptie gefilterd water & opgeloste stoffen in bloed van peritubulaire haarvaten of vasa recta Belangrijke voedingsstoffen bijna volledig 50% urea o Locatie: proximal tubule o Doorheen epitheelcellen Microvilli oppervlak vergroten o Stappen Actief transport van natrium uit cel ATP Natriumconcentratie daalt Na+ + Cl- in cel (passief) Concentratie verhoogt water in cel door aquaporins Facilitated transport energie voor actief transport glucose & aminozuren in cel 15.4.3 Tubular secretion removes other substances from blood • Tubulaire secretie o Van haarvaten tubule excretie o Regulatie verschillende chemicaliën Recap: during tubular reabsorption, nearly all the filtered water and sodium and all the major nutrients are reabsorbed from the nephron tubule. The process begins with the active transport of sodium across the cell membrane located on the capillary side of the tubular cell. Tubular secretion removes toxic, foreign, and excess substances from the capillaries. It is essential to the regulation of acid-base balance, potassium balance, and the excretion of certain wastes.
15.5 The kidneys can produce dilute or concentrated urine • The ability of the kidneys to form either dilute or concentrated urine depends on the high solute concentration in the renal medulla and the ability to alter the permeability of the collecting duct to water. • Dilute urine is formed in the absence of the hormone ADH. In the absence of ADH, reabsorption of salt without reabsorption of water continues in the collecting duct. • Concentrated urine is formed when ADH increases the collecting duct’s permeability to water, allowing water to diffuse toward the high solute concentration in the medulla. • The ability of the kidneys to produce concentrated urine is dependent upon a countercurrent mechanism that exists in the hairpin arrangements of the loops of Henle and the vasa recta.
15.5.1 producing dilute urine: excreting excess water • Teveel aan water verdunde urine o Osmotische zwelling & schade aan cellen voorkomen (water loopt cel binnen) o Stappen Dalende limb van loop of Henle • Zeer doorlaatbaar voor water • Concentratie buiten cel > in cel water uit cel diffuseren (in bloed) • Geconcentreerd vocht e 1 deel van stijgende limb • Doorlaatbaar voor NaCl & urea, niet voor water • Hoge concentratie in cel NaCl uit cel diffuseren in interstitial vocht van medulla + diffusie urea in cel 2e deel van stijgende limb • Ondoorlaatbaar voor zout, urea & water geen passief transport • Actief transport van Na+ & Cl- uit cel in interstitial vocht Recap: production of dilute urine requires the reabsorption of salt without the concurrent reabsorption of water in the ascending limb of the loop of Henle, the distal tubule, and the collecting duct
15.5.2 Producing concentrated urine: conserving water • Te weinig water geconcentreerde urine o Geregeld door antiduretic hormoon (ADH) Verhoogt permeabiliteit collecting duct voor water Reabsorptie water uit collecting duct in interstitial vocht Recap: the formation of concentrated urine requires antidiuretic hormone (ADH). In the presence of ADH, most of the water is reabsorbed from the collecting duct, leaving a small volume of concentrated urine to be excreted
15.6 Urination depends on a reflex • Urination is caused by the micturition reflex, a neural reflex initiated when the bladder is stretched. • Urination can be prevented by higher (voluntary) neural signals from the brain. • Micturition reflex o 2 sluitkleppen van urinebuis Interne: verlenging van gladde spier van blaas Externe: skeletspier vrijwillige controle o Blaas • Stretching van externe sluitklep o Signalen naar ruggenmerg onvrijwillige reflex: contractie blaas & ontspanning interne sluitspier o Signalen naar hersenen verminderde activiteit somatische bewegingsneuronen ontspanning externe sluitspier • Vrijwillig reflex opheffen: vermeerderde activiteit somatische bewegingsneuronen (door hersenen) Recap: Urination depends on the neural micturition reflex; bladder stretching initiates involuntary relaxation of the internal urethral sphincter. The brain can override the reflex by voluntary contraction of the external urethral sphincter.
15.7 The kidneys maintain homeostasis in many ways • water balance is maintained by a negative feedback loop involving ADH. Te main stimulus for the secretion of ADH is an increase in the solute concentration of the blood. • Blood volume is regulated by maintenance of the body’s salt balance, which is controlled primarily by a negative feedback loop influenced by two hormones: renin from the kidney and aldosterone from the adrenal cortex • The kidneys secrete (and excrete) H+ and NH4+ in amounts equal to the net gain of acid per day (other than as CO2). They also secrete H+ as part of the mechanism for the absorption of all filtered HCO3• The kidneys synthesize and secrete erythropoietin, the hormone responsible for the regulation of red blood cell production. • The kidneys are required for the activation of vitamin D. 15.7.1 Water balance determines blood volume and blood pressure • Waterbalans bloedvolume & bloeddruk o Negatieve feedback Concentratie bloed hoger ADH van posterior hypofyse naar nieren verhoogde permeabiliteit van collecting duct voor water o Bloedconcentratie hoger dorst o Diuresis = hoge urinestroom snelheid Diuretic: elke substantie dat vorming & excretie van urine verhoogt
15.7.2 Aldosterone, renin, and AHN control blood volume • Aldosterone, renin & ANH bloedvolume o Aldosterone Steroïd hormoon van bijnierklier Verhoogt reabsorptie Na+ doorheen distal tubule & collecting duct Zwak gereguleerd door Na+ o Renin Enzyme dat functioneert als hormoon Afgescheiden door juxtaglomerular apparatus (groep cellen van afferente kleine slagaders) o Stappen Lager bloedvolume/bloeddruk secretie renin Angiotensinogen angiotensin I angiotensin II (hormoon) Secretie aldosterone Verhoogde Na+ -reabsorptie Water vastgehouden bloedvolume stijgen o ANH Omgekeerd effect Recap: The solute concentration of blood is maintained by a feedback loop involving ADH. Renal excretion of sodium is regulated largely by aldosterone, which in turn is controlled by the secretion of renin in response to changes in blood volume of blood pressure. The hormone AHN stimulates sodium excretion.
15.7.3 Kidneys help maintain acid-base balance and blood PH • Base-zuur balans & pH bloed o Reabsorptie gefilterd HCO3 Secretie H+ H2CO3 CO2 + H2O Teveel aan H+ buffer van negatieve ionen (fosfaat & sulfaat) excretie in urine o Renale excretie van zuur als ammonium Metabolisme productie NH4+ & HCO3 NH4+ excretie in urine HCO3- diffusie in bloed o Productie RBC door erythropoietin Negatieve feedback Minder zuurstof vrijlating erythropoietin stimulatie beenmerg om meer RBC te produceren
15.7.4 Kidneys activate vitamin D • Activatie vitamine D o Functie Absorptie calcium & fosfaat Gezonde botten & tanden o UV-licht op molecule van huid productie inactieve vorm vitamine D transport naar lever (chemisch veranderd) transport naar nieren activering door parathyroid hormoon (PTH) Recap: The kidneys help maintain the body’s acid-base and blood PH by reabsorbing all filtered bicarbonate and by excreting H+. decreased oxygen delivery to the kidneys triggers the release of erythropoietin, which stimulates the production of red blood cells by bone marrow. Synthesis of vitamin D involves the skin, liver, and kidneys.
15.8 Disorder of the urinary system • The kidneys are vulnerable to damage by toxic substances, infections, sustained decreases in blood pressure, or blockage of urination outflow. • Nephrons that are damaged berond repair are not replaced • Hemodailysis is an artificial procedure for cleansing the blood of wastes and excess solutes. • Renal transplantation is technically easy and usually quite successful, but there is a shortage of donor kidneys. • Proteinuria o Aanwezigheid van proteïnen in urine 15.8.1 Kidney stones can block urine flow • Nierstenen o Wat? Mineralen in urine kristalliseren in renale pelvis o Behandeling Operatie Ultrasonische schokgolven verbrijzelen
15.8.2 Urinary tract infections are often caused by bacteria • Urinestelselinfecties o Wat? Aanwezigheid van microben in urine Infectie in urinestelsel o Oorzaak Vaak bacteriën o Symptomen Roodheid & zwelling Pijn tijdens urineren Moeilijkheden urineren Bedplassen Pijn in lage rug Bloed & pus in urine o Vaker in vrouwen kortere urinebuis
15.8.3 Acute and chronic renal failure impair kidney function • Acuut & chronisch renaal falen o Wat? Acuut • Kortstondige beschadiging aan nieren Chronisch • “end-stage renal disease” (ESRD) • Minstens 60% verlies van volledige functie o Oorzaken: acuut Lagere bloeddruk Grote nierstenen Infecties Transfusiereacties Wonden Giftige medicijnen & chemicaliën Recap: the kidneys have a huge reserve of function. However, acute or chronic renal failure can result from prolonged changes in blood pressure, disease, large kidney stones, transfusion reactions, burns, injuries, toxic substances, and other conditions such as diabetes.
15.8.4 Dialysis cleanses the blood artificially • Dialyse o Replicatie nierfunctie o Thuis: continuous ambulatory peritoneal dialysis (CAPD) Dialysevocht rechtstreeks in peritoneal holte door buikholte Vrijheid van beweging Infectierisico o Ziekenhuis: hemodialyse Machine met semipermeabele membranen Duur Neemt veel tijd in beslag
15.8.5 Kidney transplants are a permanent solution to renal failure • Niertransplantaties: permanente oplossing Recap: CAPD is an at-home dialysis technique in which fluid is placed in the peritoneal cavity and replaced at regular intervals. Hemodialysis cleanses the blood by means of an artificial kidney machine consisting of a semipermeable membrane and clean fluid. Kidney transplants are the best hope for people in renal failure. Currently there is a severe shortage of kidneys available for transplant.
Hoofdstuk 16: Reproductive Systems 16.1 The male reproductive system delivers sperm • Sperm are produced in the male reproductive organs, called the testes, and stored in the epididymis and ductus deferens. • Semen contains perm and the secretion of three glands: the seminal vesicles, the prostate gland and the bulbourethral glands. • Tens of millions of sperm are formed every throughout the male’s adult life. The production of sperm is under the control of three hormones: testosterone, LH and FSH. 16.1.1 Testes produces sperm • Zitten in balzak o Temperatuurregeling • Seminiferous tubes spermproductie • Epididymis mogelijkheid tot zwemmen • Ductus (vas) deferens mogelijkheid tot zwemmen • Ejaculatory duct • Penis 16.1.2 Accessory glands help sperm survive • Semen: dik slijm • Spermavesikels o Fructose energie o Prostaglandines induceren spiercontracties in vagina • Prostaatklier o Basis vocht pH vagina verhogen • Bulbourethral glands slijm o Wegwassen resten zure urine o ‘smering’ Recap: the male reproductive system consists of the testes where sperm are produced, a series of duct and accessory glands, and the penis. Semen consists of sperm and three glandular secretions that provide energy and the proper PH environment for the sperm and also lubrication for sexual intercourse.
16.2.3 Sperm production requires several cell division • Spermatogonia (diploid) • Mitose primary spermatocytes (diploid) • 2 x meiose secondary spermatocytes spermatids (haploid) • Cellen omgeven & gevoed door sertoli cellen • Structuur sperma o Hoofd: DNA Acrosoom penetratie door ei o Midden: mitochondrieën o Staart Recap: the haploid sperm form continuously in the seminiferous tubules from undifferentiated diploid cells called spermatogonia. Millions of sperm from every day throughout a man’s life, and a typical ejaculate contains up to 300 million.
16.2.4 Testosterone affects male reproductive capacity • Steroïd hormoon door interstitial cells • Functie o Groei & functie van weefsels o Agressief & seksueel gedrag o Secundaire geslachtsverschillen o Deling spermatogonia & steun sertoli cells • Negatieve feedback o Minder testosteron secretie GnRH (gonadotropin-releasing hormone) door hypothalamus secretie LH & FSH door anterior pituitary glan LH secretie testosteron door interstitial cells FSH stimulatie sertoli cells o Hoge concentraties inhibitie secretie GnRH, LH & FSH o Hoge activiteit sertoli cells secretie inhibin geen secretie FSH Recap: testosterone stimulates the growth and function of the male reproductive system, aggressive and sexual behavior, and development of secondary sexual characteristics. Blood levels of testosterone are regulated by a negative feedback loop involving GnRH from the hypothalamus and LH and FSH from the anterior pituitary.
16.2 The female reproductive produces eggs and supports pregnancy • The female reproductive organs (the ovaries), produce mature oocytes and release them one at a time on a cyclic basis. • Fertilization of the oocyte (if it occurs) takes place in the oviduct. • The fertilized egg makes its way to the uterus, where it implants and begins to develop into a fetus. • The vagina contains glands that produce lubricating fluid during sexual arousal. • The hormone estrogen causes the mammary glands to enlarge at puberty.
16.2.1 Ovaries release oocytes and secrete hormones • Secretie oestrogeen & progesteron • Vrijlaten oocytes eileider (buis van Fallapio) o Fimbriae beweging bevorderen o Bevruchting meestal in bovenste deel o 3-4 dagen voor in baarmoeder 16.2.2 The uterus nurtures the fertilized egg • Structuur o Buitenste laag: myometrium Gladde spieren Rekt tijdens zwangerschap Spierkracht tijdens bevalling o Binnenste laag: endometrium Epitheelweefsel, klieren, bindweefsel & bloedvaten Implantatie Vorming placenta • Baarmoederhals o Toegang sperma o Uitgang foetus Recap: the ovaries secrete estrogen and progesterone, store immature oocytes, and release generally one oocyte at a time at intervals of about 28days. The oocyte travels through the oviduct to the uterus, where implantation occurs if the egg has been fertilized.
16.2.3 The vagina: organ of sexual intercourse and birth canal • Maagdenvlies • Klieren in vagina: productie slijm ‘smering’ • Externe genitaliën: vulva o Grote schaamlippen o Kleine schaamlippen o Clitoris 16.2.4 Mammary glands nourish the infant • Tepel o Gladde spieren die kunnen samentrekken • Areola: omringt tepel • Melkproducerende lobjes • Borsten: grotendeels adipose tissue • Oestrogeen & progesteron voorbereiding lactatie • Prolactine lactatie • Oxytocine contracties voor lactatie Recap: the vagina is the female organ of sexual intercourse and the birth canal; around its opening are the structures of the vulva. Mammary glands are accessory organs that produce and store milk.
16.3 Menstrual cycle consists of ovarian and uterine cycles • The cyclic changes in the female reproductive system are called the menstrual cycle. The menstrual cycle consists of an ovarian cycle that mature oocytes, and a uterine cycle in which the uterus prepares for pregnancy. • The menstrual cycle is controlled by the hormones estrogen, progesterone, LH, and FSH. A surge in LH secretion triggers ovulation. 16.3.1 • • •
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The ovarian cycle: Oocytes mature and are released Geboorte: 1 miljoen primary oocytes (gedeeltelijk ontwikkeld) Slechts 400-500 oocytes tijdens leven Stappen o Primary oocyte omringd door granulosa cellen Follikel Verhoging GnRH secretie FSH & LH stimulatie follikel + secretie oestrogeen door follikel o Granulose cellen delen Vorming zona pellucida o Vorming antrum in follikel Granulosa cellen secretie oestrogeen & progesteron o Stage 1 meiosis secondary oocyte + polar body Graafian follikel o Secretie LH ovulatie o Corpus luteum Secretie progesteron & oestrogeen Inhibitie secretie FSH o Degeneratie corpus luteum na 12 dagen Bij bevruchting: chorion secretie human chorionic gonadotropin productie oestrogeen & progesteron door corpus luteum
Recap: During the ovarian cycle, a primary oocyte within a developing follicle divides once to form a secondary oocyte. The follicle ruptures, releases the oocyte, and forms the corpus luteum that secretes progesterone and estrogen.
16.3.2 The uterine cycle prepares the uterus for pregnancy • Begin: 1e dag menstruatie • Complete cyclus: ongeveer 28 dagen • Stappen o Dag 1 – 5 : menstruele fase Vermindering oestrogeen & progesteron Menstruatie o Dag 6 – 14: proliferatieve fase Verhoogde niveaus oestrogeen door follikel Endometrium: dikker, doorbloeder & meer klieren Baarmoederhals: slijm vergemakkelijking doorgang sperma Ovulatie o Dag 15-28: secretory fase Productie oestrogeen & progesteron endometrium 3x dikker Productie glycogen: energiebron embryo ‘cervical plug’: preventie sperma & bacterieën • PMS o Verlangen naar voedsel o Mood swings o Angst o Rug- & gewrichtspijn o Watervasthouding o Hoofdpijn Recap: Rising levels of estrogen cause the endometrium to profilate. If pregnancy does not occur, hormone levels fall and the endometrial layer disintegrates and is shed, a process known as menstruation. 16.3.4 Cyclic changes in hormone levels produce the menstrual cycle • Positieve feedback o Ovulatie o Herhaling elke maand o Trage verhoging LH ontwikkeling immature follikel + secretie oestrogeen door follikel o Lage concentratie oestrogeen inhibitie secretie LH, toch trage verhoging LH o Hoge concentratie oestrogeen stimulatie secretie LH (ovulatie) • Negatieve feedback o Constante hoge concentraties oestrogeen & progesteron (door productie door corpus luteum) inhibitie secretie LH & FSH (preventie 2e ovulatie) Recap: Ovulation is triggered by a surge of LH, which in turn is caused by the positive feedback effect of a high concentration of estrogen from the maturing follicle. During the second half of the menstrual cycle, sustained high levels of estrogens and progesterone inhibit further ovulation.
16.4 Human sexual response, intercourse, and fertilization • Both males and females are aroused by certain stimuli and respond in ways that facilitate intercourse and ejaculation. In males, the penis swells and hardens. In females, glandular secretions provide lubrication. • Both males and females experience a pleasurable reflex event called an orgasm. Orgasm is accompanied by ejaculation, or the expulsion of semen, in the male. • Sperm deposited in the vagina during intercourse make their way through the cervix and uterus and migrate up to the oviducts to the egg . Only one fertilizes the egg. 16.4.1 The male sexual response • Erectie o Neurale activiteit verwijding bloedvaten meer bloed in penis druk op bloedvaten minder bloed uit penis • Verhoging hartritme & ademen • Plateau fase: opwinding • Orgamse: ejaculatie o Sympathetische zenuwen: contractie gladde spieren klierafscheidingen o Skeletspieren ejaculatie o 3-4 ml sperma • Resolutie fase • Refractory periode
16.4.2 The female sexual response • Stimulatie neurale reflexen verwijding bloedvaten in schaamlippen, clitoris & tepels • Opwinding secretie ‘smerings’vochten • Orgasme: rhytmische contracties Recap: women and men experience the same four phases of sexual responsiveness. Sexual arousal in the male results penile erection that leads to orgasm and ejaculation. Females experience sexual arousal and pleasurable orgasms marked by rhythmic muscular contractions.
16.4.3 Fertilization: One sperm penetrates the egg • Zaadcel door baarmoederhals, baarmoeder & eierstokken • Penetratie zona pellucida Recap: during ejaculation, the male deposits several hundred million sperm in the vagina. Fertilization of the egg by a single sperm occurs within five days, if it occurs at all.
16.5 Birth control methods: Controlling fertility • The most effective methods of preventing pregnancy are abstinence and female or male surgical sterilization. Sterilization should be considered permanent, though it may be reversible. • Other effective of birth control include intrauterine devices (IUDs) and manipulation of hormone levels with pills, patches, injections, or vaginal rings. • Moderately effective methods of birth control include include condoms, cervical caps and diaphragms, and various spermicides. The “natural” methods (withdrawal and periodic abstinence) ate the least effective. • Morning-after pills are now available to be used as emergency contraceptives up to 72 hours after intercourse. 16.5.1 Abstinence: Not having intercourse 16.5.2 Surgical sterilization: Vasectomy and tubal ligation • Vasectomie bij mannen o Incisies in balzak o Localiseren ductus deferens Op 2 plaatsen vastgebonden Stuk tussenuitgehaald o Tubal ligation bij vrouwen o Incisies in buikwand o Localiseren eileiders Op 2 plaatsen vastbinden Stuk tussenuithalen o Hysteroscopie (nieuwe versie) Flexibele buis in eileiders Elektrische schokken • Meestal permanent
16.5.3 Hormonal methods: Pills, injections, patches, and rings • Pil o Oestrogeen & progesteron inhibitie secretie LH & FSH o Meestal 3 weken pil, dan 1 week niks of placebopil o Continue Seasonale: slechts 4 menstruaties per jaar Lybrel: jaar lang geen menstruatie o Voordelen Reductie krampen & menstruatie Bescherming sommige kankers o Nadelen Acné Hoofdpijn Hoge bloeddruk of bloedklontersWaterretentie • Hormooninjecties o Provera Injectie progesteron Duurt 3 maanden o Lunelle Injectie progesteron & oestrogeen Maandelijks • Huidpatchen o Nieuwe patch elke week o weken lang • Vaginale ring o 3 weken in vagina • Implantaten • Voordelen o Niet tijdens voorspel • Nadelen o Geen bescherming tegen SOA’s Recap: Abstinence and male or female surgical sterilization are highly effective methods of birth control. Hormonal methods – pills, injections, patches, and rings – are also relatively effective but can have side effect.
16.5.4 IUDs are inserted into the uterus • Intrauterine devices • Kleine stukjes plastic/metaal in baarmoeder • Milde chronische ontsteking preventie fertilisatie of implantatie • Voordelen o Effectief o Niet tijdens voorspel • Nadelen o Krampen & bloedingen o Infecties o Mogelijke schade aan baarmoeder
16.5.5 Diaphragms and cervical caps block the cervix • Latex in vagina • Nadelen o Tijdens voorspel & vlak na seks o Geen bescherming tegen SOA • Voordelen o Redelijk effecties (in combinatie met zaaddoders) 16.5.6 • • • •
Chemical spermicides kill sperm Zaaddoders Niet 100% effectief Vlak voor seks of vlak na Sommige doden sommige SOA
16.5.7 Condoms tap ejaculated sperm • Redelijk effectief als juist gebruikt • Bescherming tegen SOA Recap: Physical barriers (diaphragms, cervical caps, and condom) and chemical spermicides are moderately effective, and a few afford some protection against disease. IUDs, although more effective against pregnancy, are also more risky.
16.5.8 Withdrawal and periodic abstinence • Terugtrekking o Vaardigheid & toewijding o Risico op sperma • Periodieke onthouding o Meten van lichaamstemperatuur o Moeilijk om te weten welke 5 dagen ovulatie voorgaan Recap: Withdrawal and periodic abstinence are not effective forms of birth control in the long term.
16.5.9 Pills that can be used after intercourse • Preventie ovulatie • Blokkeren actie progesteron • Abortiepillen 16.5.10 Elective abortion • Vacuum zuigen van baarmoeder • Chirurgisch schrapen van baarmoederlining • Saline oplossing door infusie Recap: Pills can be taken after intercourse to forestall ovulation or prevent a pregnancy from continuing. Abortion is a controversial procedure that terminates a pregnancy electively.
16.5.11 The future in birth control • Mannelijke pil • Vaccinaties voor vrouwen 16.6 Infertility: Inability to conceive • Infertility is defined as the failure to achieve a pregnancy after a year of trying. Nearly 15% of all couples are infertile. • For male infertility, the primary option is artificial insemination. When the male has a low count but still some viable sperm, the sperm can be concentrated before insemination. In many cases, donor sperm are used. • Female infertility may be overcome by several methods. In in vitro fertilization, egg and sperm are combined under laboratory conditions. The fertilized egg is allowed to develop for several days and then inserted into the uterus. In GIFT, the egg and sperm are inserted directly into an oviduct immediately after collection. In ZIFT, the egg and sperm are combined first, and then the fertilized egg is inserted into the oviduct. 16.6.1 Infertility can have many causes • Mannen: gebrek aan normaal gezond sperma (minder dan 60 miljoen/ejaculatie) o Laag testosteronniveau o Immuunstoornissen o Straling o Sommige medicijnen o Sommige ziektes • Vrouwen o PID (pelvic inflammatory disease): overdreven bacteriële infecties o Abnormale prodcutie LH & FSH o Tumoren o Te zure vaginale afscheidingen of dik slijm in baarmoederhals bemoeilijken sperma o Endometriosis: endometrieel weefsel migreert door eileiders tijdens menstruele periode pijn & onvruchtbaarheid o Miskraam Recap: Male fertility is an insufficiency of lack of sperm. Causes of female infertility are variable and include failure to ovulate, damage to oviducts, pelvis inflammatory disease, secretions that impair sperm function, uterine tumors, endometriosis, age-related changes and miscarriages.
16.6.2 Enhancing fertility • Kunstmatige inseminatie o Sperma met spuit in vagina of baarmoeder, zo dicht mogelijk tegen ovulatie aan o Vooral aangewezen bij Gebrek aan normaal, gezond sperma Mannen die geen sperma produceren (anonieme donor) Single moeders • In vitro fertilisatie o ‘testbuisbaby’s o Met naald immature eicellen verzamelen o Laten rijpen in steriele omstandigheden o Sperma toevoegen o Als cel begint te delen terug in baarmoeder o Vooral aangewezen bij Beschadigde eileiders Vrouwelijke afscheidingen die contact eicel-sperma belemmeren o 20% slaagkans Vaak meerdere eicellen tegelijk geboorte van tweelingen/drielingen/… • GIFT & ZIFT o Gamete IntraFallopian Transfer Onbevruchte eicellen & sperma samen in baarmoeder geplaatst door kleine incisie in buikwand o Zygote IntraFallopian Transfer Bevruchte eicel door kleine incisie in buikwand in baarmoeder geplaatst • Medicijnen o Productie eicellen verhogen o Meestal gegeven voor IVF o Geboorte van tweelingen/drielingen/ • Draagmoederschap Recap: A variety of methods are available to improve fertility; the choice varies according to the cause of the infertility. Options include artificial insemination, in vitro fertilization, gamete intrafallopian transfer, zygote intrafallopian transfer, fertility-enhancing drugs, and surrogate motherhood.
16.7 Sexually transmitted diseases: A worldwide concern • The common feature of sexually transmitted diseases (STDs) is that they are transmitted during sexual contact. Their disease effects are not necessarily on the reproductive system. • Bacterial STDs include gonorrhea, syphilis, and Chlamydia. Syphilis is the most dangerous; Chlamydia, the most common. All are treatable with antibiotics. • Viral STDs include HIV (the virus that causes AIDS), hepatitis B, genital herpes, and genital warts (HPV). HIV is particularly deadly, and there is as yet no cure. There are now vaccines for hepatitis B and HPV. • Avoiding the diseases caused by STDs is a matter of reducing your risk of exposure and paying attention to (and taking responsibility for) your own health.
16.7.1 Bacterial STDs: Gonorrhea, syphilis, and Chlamydia • Gonorrhea o Neisseria Gonorrhoeae o Overdraging: 50% bij vrouwen, 20% bij mannen na Seksueel contact Oraal-genitaal contact Mond & ogen via handen o Symptomen Man: pijnlijke urinatie & verschijning van pus uit penis Vrouwen: brandend gevoel tijdens urinatie & vaginale afscheiding Ontsteking Littekens Steriliteit o Genezing:antibiotica •
Syfillis o Treponema pallidium o 3 fasen Fase 1: 1-8 weken na infectie • Chancre op infectieplaats Fase 2 • Valt lymfeknopen, bloedvaten, spierweefsel, been & zenuwstelsel aan • Uitslag • Haarverlies • Grijze vlekken infectie op spierweefsel Fase 3 • Schade aan cardiovasculair & zenuwstelsel • Blindheid • Huidzweren • Dood o Genezing: penicilline
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Chlamydia o Chlamydia trachomatis o Symptomen Mannen: afscheiding van penis + brandend gevoel tijdens urinatie Vrouwen: vaginale afscheiding + brandend en jeukend gevoel o Gevolgen PID Permanent litteken op buizen van Fallopio Zwangerschapscomplicaties Steriliteit
Recap: Major bacterial STDs include Gonorrhea, syphilis, and Chlamydia. If not treated, gonorrhea and Chlamydia can cause inflammation and sterility; syphilis can cause widespread damage to body systems and eventual death.
16.7.2 Viral STDs: HIV, hepatitis B, genital herpes, and HPV • HIV: zie hoofdstuk 9 • Hepatitis B o Ontsteking van lever o Overgedragen via bloed of lichaamsvochten o Vaccin beschikbaar • Genitale herpes o Herpes simplex virus type 2: seksueel/huid-op-huid contact o Herpes simplex virus type 1: oraal-genitaal contact o Geen medicijn • Human Papillomavirus (HPV) o Wratten o Verhoogt kans op baarmoederhals-/peniskanker o Vaccin beschikbaar (Gardasil) Recap: The most dangerous viral STD is HIV. Hepatitis B can be prevented by a vaccine. Genital herpes is irritating but not particularly deadly. HPV can cause warts and is a risk factor for cervical cancer – it, too, can be prevented by a vaccine.
16.7.3 Other STDs: Yeast infections, trichomoniasis, and public lice. • Schimmelinfecties o Bv. Candida albicans o Altijd aanwezig in mond, darm & vagina, soms teveel o Symptomen Pijn Ontsteking Dikke, kaasachtige vaginale afscheiding Mannen: afscheiding penis & pijnlijke urinatie • Trichomoniasis o Trichomonas vaginalis o Symptomen Man: ontsteking penis + afscheiding Vrouwen: schuimige, stinkende afscheiding o Gevolgen: vaginitis (ontsteking vagina) • Schaamluizen Recap: Yeast, normally present in the vagina, can multiply and cause a yeast infection; trichomoniasis results from infection by the protozoan Trichomonas vaginalis. Pubic lice are tiny arthropods that are transmitted during intimate contact or by contact with clothes or bedding.
16.7.4 • • •
Protecting yourself against STDs Selectie partner: monogame relatie met iemand die je vertrouwt & kent Communicatie (eigen gezondheid ook kennen!) Bescherming tegen SOA’s gebruiken (condooms, …)
Recap: you can reduce your risk for contracting an STD with a little effort. Choose your partner wisely, use a barrier method of birth control, and, if you suspect you have a disease, get tested promptly.
Hoofdstuk 17: Cell Reproduction and Differentiation 17.1 The cell cycle creates new cells • Cells reproduce by a repetitive cycle called the cell cycle in which one cell grows and then divides in two. • The cell cycle has two primary phases: interphase and the mitotic phase. During interphase the cell grows and the DNA is replicated. During the mitotic phase, first the nucleus and then the cell divide in two. • Interfase: groei cel & duplicatie DNA o G1-fase Periode tussen laatste deling & DNA-synthese Zeer actieve celgroei o S-fase Chromosomen gedupliceerd Tragere groei o G2-fase Trage groei cel •
Mitotische fase: deling nucleus & cytoplasma o Mitose Deling DNA in 2 sets Deling nucleus o Cytokinesis Cytoplasma delen Vorming 2 nieuwe cellen (dochtercellen)
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Complete cyclus: 18-24 uur o S-fase: 7-8 uur o Mitotische fase: 30-45 minuten
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Na celdeling: soms G0-fase o Geen groei of deling o Bv. Neuronen & osteocyten
Recap: Cell reproduction is required for growth and to replace cells throughout life. The cell cycle consists of a long growth phase (interphase), during which the cell’s DNA is replicated, and a shorter phase (mitotic phase), during which first the nucleus and then the cell cytoplasm divide.
17.2 Replication, transcription, and translation: An overview • Human DNA is packed into 45 separate molecules called chromosomes • A gene is the smallest functional unit of a chromosome. A gene contains the code for making a specific protein • DNA replication is a process in which the two strands of DNA separate and a new complementary copy is made of each strand • DNA is repaired when it is damaged and is checked for errors after it is replicated • For a gene to be expressed, the strand of DNA with that gene must be transcribed to create a complementary strand of mRNA. The mRNA leaves the nucleus, attaches to a ribosome, and serves as the template for protein synthesis. • Translation is the process of making a polypeptide chain (protein) using the mRNA as a template. Three successive bases of mRNA, called a codon, code for a particular amino acid. • The amino acid building blocks for the polypeptide chain are captured in the cytoplasm by tRNA, brought to the mRNA, and attached to each other by ribosomal enzymes. Recap: Human DNA is organized and arranged on 46 chromosomes within the cell nucleus. A gene is the smallest unit of DNA. Before a cell divides, its DNA is duplicated during the process of replication.
17.2.1 Replication: Copying DNA before cell division. • Ontrollen DNA-helix: complementaire strengen o Thymine – adenine o Guanine – cytosine o Op verschillende plaatsen in helix in tegengestelde richting tot ze elkaar tegenkomen • Vorming nieuwe complementaire streng door polymerases • 2 zusterchromatiden verbonden met centromeer • Mutaties o Nodig voor evolutie o Soms schadelijk (doorgegeven aan volgende cellen of geen DNA-replicatie meer mogelijk) o Oorzaken Fouten in replicatie Chemicaliën Fysische krachten • Mechanismen van herstel o DNA repair enzymes Fouten herkennen Uithalen & verplaatsen beschadigde stuk Herverbinden DNAstreng o Actiefst tussen DNA-replicatie & begin van mitose o Gestuurd door genen die coderen voor enzymen Recap: During replication, the two strands of DNA unwind and separate from each other. Each strand serves as a template to form a new complementary strand. Enzymes called DNA polymerases add new nucleotides to each of the old strands in order to build to complete molecules of DNA from one. Recap: mutations may result from mistakes in DNA replication of from physical of chemical damage. Repair mechanisms remove and replace damaged DNA, if possible, before replication.
17.2.2 Transcription: converting a gene’s code into mRNA • Kopie van DNA van gen naar mRNA • Gelijkaardig aan replicatie, uitzonderingen o Enkel segment van 1 gen ontward o Slechts 1 van 2 DNA-strengen (RNA is enkelvoudig) o Thymine uracil o Suikergroep is ribose (ipv desoxyribose) • RNA polymerase bindt aan promoter: begin elk gen primary transcript (messenger RNA) o Bestaat uit introns & exons (dragen genetische informatie) o Triplet code = codon 20 aminzouren ≠ codons = aminozuur AUG = start codon Recap: transcription converts short segments of DNA representing single genes into a readable and transportable mRNA code. Only a portion of the DNA molecule unwinds, and only one strand is used to make single-stranded RNA. In the final edited mRNA molecule, three successive bases, called a codon, encode for a particular amino acid.
17.2.3 Translation: Making a protein from RNA • Translatie mRNA in aminozuren • Transfer RNA met anticodon (complementair aan codons) o Bindt aan enkelvoudig aminozuur en brengt naar juiste plek op mRNA • Ribosoom o Bindt aminozuren tot proteïne o Bestaat uit ribosomal RNA (rRNA) & proteïnen • 3 stappen o Initiatie Initiator tRNA aan ribosoom & mRNA o Verlenging o Beëindiging Stop-codon op mRNA Recap: translation is a three-step process (initiation, elongation, and termination) by which proteins are assembled according to an mRNA code. In the process, tRNA molecules are used to capture the amino acids in the cytoplasm specified by each mRNA codon. The amino acids are connected together on a ribosome, which binds both mRNA and tRNA.
17.3 Cell reproduction: One cell becomes two • Mitosis is a sequence of events in which the replicated chromosomes are separated to form two new genetically identical nuclei. • Cytokinesis is the process whereby the cell divides into two new cells, each with one of the new nuclei produced by mitosis and roughly half of the cell’s organelles and mass. • Meiosis is a sequence of two cell divisions that produce haploid cells. Meiosis occurs only in cells destined to become sperm or egg. Crossing-over during meiosis mixes the genes of homologous chromosomes, and subsequent cell division reduce the number of chromosomes by half.
17.3.1 • • •
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Mitosis: Daughter cells are identical to the parent cell Deling nucleus waarbij zusterchromatiden gescheiden worden van elkaar Zelfde set DNA Verschillende fases o Profase Gedupliceerde chromosomen zichtbaar Vorming centrosoom (spoelfiguur) van cytoskelet Centriolen naar verschillende kanten van cel Celmembraan lost op Centromeer 2 verschillende structuren o Metafase Chromosomen op 1 lijn in midden spoelfiguur o Anafase DNA moleculen delen & naar verschillende kant cel Energie in vorm van ATP Begin cytokinesis o Telofase Oplossen spoelfiguur Nieuwe celmembranen rond chromosomen Vorming diploïde cellen (2x23 chromosomen: 22 paar autosome chromosomen + 1 paar sexchromosomen)
Recap: Mitosis is the process by which the cell nucleus containing duplicated chromosomes divides in two. During mitosis, the sister chromatids of a duplicated chromosome are separated, resulting in two daughter cells with complete sets of DNA. The duplicated chromosomes become visible in prophase, align along the center of the cell in metaphase, are pulled apart in anaphase and move to opposite sides of the cells and become surrounded by new nuclear membranes in telophase.
17.3.2 Cytokinesis divides one cell into two identical cells • Proces waarbij een cel deelt om dochtercellen te creëren • Samentrekbare ring rond elk deel chromosomen o Loodrecht op as spoelfiguur zeker van 1 kern per cel o Gemaakt uit restanten cytoskelet vlak voor cytokinesis o Na deling uit elkaar nieuwe cytoskelet dochtercellen Recap: During cytokinesis, a contractile ring of microfilaments pinches the cell into two cells. Each daughter cell contains a nucleus identical to that of the parent.
17.3.3 Mitosis produces diploid cells and meiosis produces haploid cells 17.3.4 Meiosis: preparing for sexual reproduction • Meiose I: verschillen met mitose o Profase: crossing over van chromosomen recombinatie DNA o Metafase – telofase: homologe paren van elkaar gescheiden (ipv duplicaten) • Meiose 2 o Zelfde als mitose o Geen duplicatie chromosomen
17.3.5 Sex differences is meiosis: four sperm verses one egg • Geslachtsverschillen o Mannen: meiose 4 even grote maar genetisch verschillende zaadcellen o Vrouwen Zoveel mogelijk cytoplasma naar 1 dochtercel Rest: polaire lichamen Meiose 2 niet voltooid voor bevruchting Recap: meiosis is a two-step process in which the nucleus and cell divide twice, producing sperm or eggs with the haploid number of chromosomes. Crossing-over ensures that sperm (and eggs) are genetically different from each other because they contain a mixture of genes from each parent.
17.4 How cell reproduction is regulated • Cell reproduction is regulated in part by selective gene expression. Selective gene expression is controlled by regulatory genes. • The cell cycle may be influenced by the physical and chemical environments both inside and outside the cell. • Intern controlemechanisme o Cel klaar voor volgende fase? o Belangrijkste: einde G1-fase • Buiten cel o Beschikbaarheid voedingsstoffen o Beschikbaarheid hormonen & groeifactoren o Aanwezigheid andere cellen: contact vrijlating hormoon inhibitie celdeling Vooral bij weefselgroei & orgaangrootte Recap: an internal cyclic control mechanism regulates the cell cycle. The cycle can be stopped at certain checkpoints by internal surveillance systems and is influenced by conditions outside the cell.
17.5 Environmental factors influence cell differentiation • Differentiation is the process by which cells become different from each other, acquiring specialized forms and functions • Because all cells have the same set of genes, differentiation in the early embryo must be triggered be environmental influences • Cell differentiation later in development can be influenced by environmental cues, but it also depends on the developmental history of the cells that preceded it. 17.5.1 • • •
•
Differentiation during early development Elke cel kleiner (door celdeling terwijl ruimte niet groter wordt) 8 cellen elke cel zelfde omgeving Meer dan 8 cellen verschillende omgeving o Buitenste cellen: omringende vocht o Binnenste cellen: extracellular fluid tussen cellen o Activeren verschillende genen Celdifferentiatie begint lang voor homeostatische feedbackmechanismen ontwikkelen
Recap: Differentiation is the process whereby cells become different from each other. During early development, environmental influences trigger differentiation.
17.5.2 Differentiation later in development • Gevormd door 2 factoren o Ontwikkelingsgeschiedenis o Lokale omgeving • Foetus kwetsbaarder voor genetische schade • Oorzaken o Sigarettenrook o Alcohol o Medicijnen o Illegale drugs o Chemicaliën o Straling o Infecties Recap: some genes are expressed only at certain stages of development; for this reason, genetic mutations during early development can be particularly damaging. Later in development hundreds of different genes may be expressed by various types of cells. Agents that can harm a fetus include cigarette smoke, alcohol, legal and illegal drugs, chemicals, radiation, and bacterial and viral infections.
Hoofdstuk 18: Cancer: Uncontrolled Cell Division and Differentiation 18.1 Tumors can be benign or cancerous • Normal cells have two key characteristics: (1) their rates of division are kept under control, and (2) most remain in one location in the body. • A mass of cells that is dividing more rapidly than normal is called a tumor. Some tumors are benign. • Verhoging in snelheid celdivisie = hyperplasia • Tumor = sneldelende cellen die massa vormen o Goedaardig Blijven op 1 plaats Kunnen gevaarlijk zijn geen plaats voor andere cellen o Kankerachtig 18.2 Cancerous cells lose control of their functions and structures • Cancer develops when cells divide uncontrollably, undergo physical changes, and no longer adhere to each other • Eventually some cancer cells invade nearby tissues. Others metastasize, colonizing distant sites. • Cancer is the second leading cause of death in the US • Dysplasia = abnormale structuur o Grotere celkern o Minder cytoplasma o Geen gespecialiseerde functie & structuur o Meestal teken van pre-kankerachtig o Bv. Actinic keratosis: droge, schilferige of harde huidletsels • Tumor = kanker o Sommige cellen alle controle van organisatie, structuur & regulatie verliezen Cellen groeien & delen oncontroleerbaar Fysieke veranderingen verplaatsen o In situ kanker: blijft op dezelfde plaats o Uitspreiden o Kwaadaardige tumoren Uitspreiding Vallen normaal weefsel aan Recap: some tumors are benign, but when tumor cell change form dramatically and divide uncontrollably, the tumor is called cancer. Cancer becomes malignant when cells invade and metastasize, starting new tumors at distant sites.
18.3 How cancer develops • Mutations of proto-oncogenes, tumor suppressor genes, and/or mutator genes may contribute to cancer • Inheritance of one or more mutated genes from your parents may increase your risk of developing certain cancers • Known carcinogens include some viruses and bacteria, environmental chemicals, tobacco, radiation, and dietary factors, such as faulty DNA replication and internally produced chemicals, can also contribute to cancer. • Cancer is a multifactorial disease. Perhaps six or more mutations may need to be present before a cell becomes cancerous. 18.3.1 Mutant forms of proto-oncogenes, tumor suppressor genes, and mutator genes contribute to cancer • Verschillende genen o Structurele genen proteïnen voor celgroei, divisie & differentiatie o Regulator genen proteïnen voor activatie/onderdrukking structurele genen Groeifactoren & groei-inhibitoren Proto-oncogenen: promoten celgroei • Oncogenen: beschadigd/gemuteerd • 1 oncogeen niet genoeg om kanker te ontwikkelen Tumor supressor genen • Blokkeren celgroei • Bv. p35: preventie deling beschadigde/gestresseerde cellen o Mutatorgenen Zorgen voor herstelling beschadigd DNA Mutatie cel kwetsbaar voor fouten in DNA-replicatie Recap: Proto-oncogenes and tumor suppressor genes normally control the rate of cell division. Mutator genes are involved in DNA repair. Mutations of any of these genes may contribute to cancer.
18.3.2 A variety of factors can lead to cancer • Leeftijd • Erfelijkheid o Enkele beschadigde genen van ouders • Cancerogenen: kankerverwekkende stoffen o Virussen & bacteriën (15%) HPV baarmoederhals & penis Hepitatis B & C lever HIV Kaposi’s sarcoma, non-Hodgkin’s lymphoma Epstein-Barr virus Hodgkin’s disease & non Hodgkin’s lymphoma Human T-cell leukemie/lymphoma virus HTLV-1, T-cell non Hodgkin’s Lymphoma Heliobacter pylori maag o Chemicaliën o Tabak Dodelijkste cancerogeen: 30% van alle kankerdoden o Straling (2%) Zon & radioactief gas Ultraviolet B stralen: 80% huidkankers, bv. Melanoma o Voeding (30%) Obesitas Hoge zoutopname maag Alcohol borst, endeldarm, darm & lever Schimmels & planten Fruit & groenten milde bescherming o Interne factoren Fouten tijdens DNA-replicatie Chemicaliën in lichaam • Vrije radicalen • Bijproduct van metabolisme • Normaal geneutraliseerd door peroxisomen & antioxidanten (vitaminen) Recap: aside from heritable susceptibility, factors that may contribute to the development of cancer include viruses and bacteria, environmental chemicals, tobacco, radiation, dietary factors, and alcohol. Free radicals created during cellular metabolism may also contribute to cancer.
18.3.3 The immune system plays an important role in cancer prevention • Zelf-proteïnen weg aangevallen door immuunsysteem • Sommige kankers onderdrukken immuunsysteem Recap: The immune system normally protects us from cancer cells by killing them before they spread. Immune system suppression allows cancers to develop more easily.
18.5 Cancer treatments • Many cancers are treatable; early diagnosis is important • Conventional treatments for cancer include surgical removal of the tumor, radiation, and chemotherapy • Newer treatments include magnetism and photodynamic therapy to target malignant cells precisely, immunotherapy to activate the patient’ immune system, drugs to inhibit angiogenesis and cut off the tumor’s blood supply, and molecular treatments that target specific genes. 18.5.1 Conventional cancer treatments: surgery, radiation, and chemotherapy • Bestraling o Doodt/beschadigt kankercellen o Normale cellen herstellen rapper dan kankercellen o Vaak beschadiging/doding normaal weefsel • Chemotherapie o Toediening cytotoxische chemicaliën o Werking Hinderen DNA-replicatie Vaak ook bij normale cellen die snel delen, bv. Beenmergcellen o Nadelen Misselijkheid & braken Haarverlies Bloedarmoede Vatbaarder voor infecties (minder RBC) Sommige tumoren resistent
18.5.2 Magnetism and photodynamic therapy target malignant cells • Magnetisme o Magneet in tumor o Metalige korrels in bloed o Magneet korrels naar tumoren kankercellen vernietigen • Fotodynamische therapie o Licht-gevoelige medicijnen die naar kankercellen toegetrokken worden o Laserlicht op tumor chemische gebeurtenissen doden kwaadaardige cellen 18.5.3 Immunotherapy promotes immune response • Ondersteuning immuunsysteem • Productie antilichamen die kankercellen merken 18.5.4 “Starving” cancer by inhibiting angiogenesis • Tumoren groei nieuwe bloedvaten (angiogenesis) energiebehoefte • Antiangiogenic medicijnen
18.5.5 Molecular treatments target defective genes • Vallen defecte genen aan • Gentherapie: defecte genen hersteld of vervangen Recap: the mainstays of cancer treatment are surgery, radiation, and chemotherapy. Recent advances include magnetism, photodynamic therapy, immunotherapy, drugs to inhibit angiogenesis, and molecular treatments that focus on specific defective genes.
18.7 Most cancers can be prevented • Some cancers will occur despite our best efforts because we cannot control inherited risk factors • However, most cancers could be prevented. The single most effective way to reduce cancer deaths is to reduce the rate of smoking • A healthy diet will also decrease your cancer risk. Eat lots of fruits, vegetables, legumes, and grains; reduce your intake of saturated fat, red meat, and salt • Other preventive strategies include knowing your family’s health history, examining yourself for cancer and getting regular medical screenings, maintaining a healthy weight, avoiding direct sunlight and sunlamps, drinking alcohol in moderation if at all, and staying informed. • Niet roken • Gewichtige voeding • Weinig blootstelling aan zon o Vermijden tussen 10 & 16 uur o SPF 15 of hoger • Familiegeschiedenis kennen • Regelmatige onderzoeken voor kanker • Zelf-onderzoek technieken • Weinig alcohol Recap: Most cancers could be prevented; smoking is by far the leading preventable risk factor. Other prevention strategies include knowing you family history, getting regular medical screenings, learning self-examination techniques, avoiding sunlight and sunlamps, watching your diet and weight, drinking alcohol in moderation if at all, and staying informed.
Hoofdstuk 21: Development and Aging 21.1 Fertilization occurs when sperm and egg unite • Sperm and egg meet (and fertilization occurs) in the upper third of the oviduct • Enzymes in the head of the sperm create a pathway through the corona radiata and the zona pellucida to the egg cell membrane • Entry of the sperm nucleus triggers the completion of meiosis II by the secondary oocyte. Thereafter the nuclei of sperm and egg fuse, creating a single diploid cell, the zygote. 21.1.1 The journeys of egg and sperm • Eicel o Eierstokken eileiders baarmoeder o Geholpen door cilia • Sperma o Vagina baarmoeder o Obstakels Prop baarmoederhals Juiste eileider binnengaan Zure omgeving Bacteriën & witte bloedcellen vermijden o Duurt uren Recap: Sperm must swim from the vagina, where they are deposited, through the uterus and up the correct oviduct to meet the egg. Relatively few sperm survive the journey.
21.1.2 One sperm fertilizes the egg • Eicel: structuur o Secondary oocyte (geen meiose II) o Omgeven door zona pellucida & laag cellen: corona radiata o Veel cytoplasma • Sperma o Acrosoom (hoofd) enzymen weg banen o 1e spermacel contact met celmembraan oocyte proteïnen sperma op receptorproteïnen celmembraan ondoordringbaar • Bevruchting: nucleus spermacel binnen in eicel o Vervollediging meiose II ovum o Smelten diploïd Recap: when sperm contact the egg they release enzymes that clear a path through the corona radiata and zona pellucida. Fertilization begins when one sperm’s nucleus enters the oocyte and ends when the haploid nuclei of sperm and eggs fuse, creating a new diploid cell.
21.1.3 Twins may be fraternal or identical • Kans van 1/90 • Twee-eiige tweeling o Ovulatie van meer dan 1 eicel per cyclus o Even verschillend als gewone broers & zussen (kunnen van verschillend geslacht zijn • Eeneiige tweeling o 1 enkele zygote: bal cellen breken voor differentiatie begint o Genetisch hetzelfde Recap: fraternal twins result from the fertilization of two separate eggs. Identical twins occurs when a single fertilized eggs divides in two before differentiation has begun.
21.2 Development: Cleavage, morphogenesis, differentiation, and growth • Development begins by a process called cleavage and then proceeds with morphogenesis, differentiation, and growth • The periods of development prior to birth are known as pre-embryonic (the first two weeks), embryonic (weeks three through eight), and fetal (weeks nine to birth) • Scheiding o Celdelingen zonder groei & differentiatie o Tijdens eerste 4 dagen na bevruchting o Enige beschikbare energie: opgeslagen in cytoplasma + glycogen • Morfogenesis o Dramatische veranderingen in vorm & grootte • Differentiatie o Gespecialiseerde vormen & functies o Belangrijkste reden van morfogenesis • Groei o Foetus ingebed in endometriele lining & voedingsstoffen van moeder o Elke celdeling dochtercellen verdubbelen in massa Recap: The four processes associated with development are (1) cleavage, a series of cell divisions producing a ball of identical cells; (2) morphogenesis , a sequence of physical changes; (3) differentiation, as cells assume specialized forms and functions; and (4) growth in size. Pregnancy is divided into three trimesters.
21.3 Pre-embryonic development: The first two weeks • during the first two weeks of development, the single cell develops into a hollow ball with an embryonic disk in the center that will eventually become the embryo • at about one week the pre-embryo (now called a blastocyst) begins to burrow into the uterine wall, a process called implantation • Scheiding 32 identieke cellen: morula (in eileiders) • Blastocyst (na 4 dagen) o Door differentiatie & morfogenesis o Trophoblast: buitenste laa o Lege centrale holte o Groep cellen: inner cell mass embryo • Dag 6-7: implantatie o Ingebed in endometriele lining o Voedingsstoffen van moeder • 2 week o Vorming 2e centrale holte vruchtvlies (amnion) o Celmassa embryonische disk ectoderm & endoderm • Buitenbaarmoederlijke zwangerschap: implantatie in eileider ipv in baarmoeder Recap: During pre-embryonic development, successive cleavages yield a morula. Early stages of differentiation and morphogenesis cause the morula to become a blastocyst, which implants in the lining of the uterus. The embryonic disk is destined to become the embryo.
21.4 Embryonic development: weeks three to eight • Embryonic development is marked by the presence of three primary germ layers (ectoderm, mesoderm, and endoderm) in the embryonic disk • During development the embryo is completely surrounded by two membranes. The amnion contains amniotic fluid, and the chorion develops into fetal placental tissue. Two other membranes (the allantois and the yolk sac) have temporary functions only. • By the fifth week the embryo begins to take on distinctly human features • By the eight week the placenta and umbilical cord circulation are fully functional, and male or female gonads have begun to develop
21.4.1 Tissues and organs derive from three germ layers • Embryo vanaf vorming mesoderm • Ectoderm o Buitenste laag o Epidermis huis o Zenuwstelsel o Haar o Nagels o Email van tanden o Deel van ogen o Borstklieren • Endoderm o Binnenste laag o Lever o Pancreas o Alveoli longen o Lining urineblaas, urethra & vagina o Verschillende klieren • Mesoderm o Middelste laag o Spieren o Bindweefsel o Botten o Nieren & nierleiders o Ballen/eierstokken o Beenmerg o Lining bloedvaten o Dermis huis o Lymfevaten • Snelle differentiatie, groei & morfogenesis Recap: By the beginning of the embryonic development the embryo compromises three primary germ layers, called ectoderm, mesoderm, and endoderm, that ultimately give rise to fetal tissues an organs
21.4.2 Extra-embryonic membranes and the placenta • Rond embryo o Amnion (vruchtvlies): binnenste laag Vruchtwater Absorbatie fysieke schokken Foetus isoleren Tegen uitdroging o Dooierzak Deel van spijsverteringsstelsel Productie bloedcellen o Chorion: buitenste laag Afkomstig van trophoblast Bron van human chirionic gonadotropin (HCG) Exchange mechanisme in placenta • Placenta & navelstreng o Vorming Cellen chorion enzymen endometriumweefsel oplossen & bloedvaten vorming kleine bloedgevulde holtes chorionic villi o Rest: zie ontwikkelings Recap: Four extra-embryonic membranes serve varying functions: (1) the amnion cushions the fetus and preserves it from dehydration; (2) the allantois forms blood vessels of the umbilical cord; (3) the yolk sac forms part of the digestive tract and produces fetal blood cells and reproductive germ cells; (4) and the chorion secretes hCG and forms structures that will become part of the placenta. The placenta is the site of nutrient and gas exchange between embryo and mother, and it secretes hormones. The umbilical cord joins the embryo to the placenta.
21.4.3 The embryo develops rapidly • Week 3 - 5 o Primitieve spleet langer worden met axis o Neurale spleet van ectodorm hersenen & ruggengraat o Mesoderm somites bot, spier & huid o Pharyngeal arches nek, gezicht & mond o Consistent voor alle vertebraten • Week 5 – 8 o Menselijke vorm herkenbaar • Soms miskramen: 20% gevallen Recap: Embryonic development is rapid an dramatic. By the fifth week the embryo is becoming distinctly human in form, and by eight weeks it is an inch long. The natural rate of miscarriages through eight weeks of development may be as high as 20%
21.5 Gender development begins at six weeks • Until six weeks and embryo is “sexually indifferent” • The presence or absence of a Y chromosome determines whether the embryo will become phenotypically male or female • Ongedifferentieerde urogenitale spleet • Gen SRY op Y chromosoom o Proteïne testis-determining factor o Ontwikkeling ballen o Secretie testosteron door ballen o Secretie anti-Mullerian door ballen onderdrukking ontwikkeling vrouwelijke genitaliën Recap: Gender development begins at about 6weeks. The presence of a Y chromosome signals the embryo to develop into a male; the absence of a Y chromosome causes the embryo to develop into a female.
21.6 Fetal development: nine weeks to birth • Months 3-9 are marked by rapid growth and development of the organ systems. By the fifth month the fetus begins to move • By the sixth month, life outside the womb is possible with good medical care 21.6.1 Months three and four • 3e maand o Nieren o Ledematen o Skelet met bot o Milt bloedcellen o Lever o Genitaliën • 4e maand o Lever & beenmerg bloedcellen o Gezicht o Meisjes: follikels in eierstokken
21.6.2 Months five and six • Maand 5 o Zenuwstelsel & skeletspieren beweging o Huid o Hartslag • Maand 6 • Overleven buiten baarmoeder • Reactie op externe stimuli • Longen
21.6.3 Months seven through nine • Rappe groei & maturatie • Beweging ogen • Verhoogde activiteit • Ballen in balzak • Geboorte: 38 weken Recap: The period of fetal development extends from nine weeks to birth at 38 weeks. Growth is rapid, with the mature fetus weighing approximately 6-7,5 pounds at birth. The fetus begins to move at about five months, and life outside the womb is at least possible by about six months when the lungs begin to produce surfactant.
21.7 Birth and the early postnatal period • Birth occurs at about 38weeks of development (nine months) • The three phases of labor are dilation, expulsion, and afterbirth. • Shortly after the new born takes its first breath, the newborn’s cardiovascular system undergoes substantial changes. Within hours or a few days the umbilical vessels regress and the ductus arteriosus and foramen ovale close, rerouting all blood through the pulmonary circulation 21.7.1 Labor ends in delivery • Uitgelokt door fetal pituitary gland o Secretie ACTH secretie steroide hormonen door bijnier placentie meer oestrogeen & minder progersteron o Oestrogeen oxytocinereceptoren verhogen & productie prostaglandinen baarmoeder ritmisch samentrekken • Positieve feedback o Ritmische contracties baarmoeder secretie oxytocin • 3 stages o Ontsluiting 6-12 uur Baarmoederhals naar achter Druk foetus op baarmoederhals ontsluiting 10 centimeter vruchtvlies breken o Uitdrijving Drang om mee te duwen Eerst hoofdje, dan rest Navelstreng doorknippen baby zelf ademen Minder dan 1 uur o Nageboorte Uitdrijving placenta Minder dan halfuur na geboorte kind Recap: labor and delivery take about 24 hours or less. The dilation phase is marked by widening of the cervix and increasingly frequent and strong uterine contractions. The fetus emerges in the shorter (one hour or less) expulsion phase. The placenta and umbilical cord are expelled during the afterbirth phase.
21.7.2 Cesarean delivery: surgical delivery of a baby
21.7.3 The transition from fetus to newborn • Eerste adem nemen o Vergemakkelijkt door pulmonary surfactants reduceren druk o CO2-niveau daalt hersenen signalen zenden • Veranderingen in cardiovasculair stelsel o Foetus: bloed binnen via navelstreng & niet door lever o Foetus: bloed buiten via navelstreng o Foetus: doorgang tussen linker- & rechteratrium meeste niet langs longen o Foetus: shortcut van pulmonary arteries naar aorta 21.7.4 Lactation produces milk to nourish the newborn • Tijdens zwangerschap o Hoge concentraties oestrogeen & progesteron o Borsten groter worden o Melkproductie verhinderd door verhindering werking prolactin (door oestrogeen & progesteron) • Na geboorte o 1e dagen: colostrum Veel antilichamen Weinig vet & lactose o Later: Veel vet & lactose groei baby Oxytocin: contracties Recap: at birth a sharp increase in carbon dioxide causes the newborn to take the first breath. Shortly after birth the umbilical blood vessels and ductus arteriosus regress, and anatomical changes in the heart reroute all blood through the lungs. Prolactin stimulates lactation, and oxytocin stimulates the release of milk during suckling.
21.8 From birth to adulthood • Human neonates are relatively helpless because the nervous and muscular systems are not yet mature • There is a disproportionate increase in the development of the musculoskeletal and nervous system during infancy. The immune system remains relatively immature • Body shape changes in childhood. The brain achieves 95% of its adult size • Adolescence is marked by the last spurt of rapid growth and the attainment of sexual maturity 21.8.1 The neonatal period: a helpless time • Zenuwstelsel & spieren niet volgroeid hoofd ondersteunen • Geen lange-termijn herinneringen Recap: The neonatal nervous and muscular systems are not well developed. Neonates are physically helpless and cannot form memories
21.8.2 Infancy: Rapid development and maturation of organ systems • Snelle groei • Gewicht verdriedubbelen • Botten harder • Meer spiermassa & kracht • Helft van hersengroei o Cerebrale Corte • Eerste tanden: 6 maand • 14 maanden: stappen • Veel slaap • Immuunsysteem achter vaccinaties op bepaalde tijdstippen Recap: Infancy is marked by rapid growth and continued maturation of organ systems. Infants begin to eat solid foods and to walk. The immune system develops more slowly than other organ systems.
21.8.3 Childhood: continued development and growth • 95% hersenen volgroeid • Spierkracht & motorcoördinatie • Buikspieren buikje verdwijnt • Alle orgaansystemen volledig functioneel o Uitzondering: reproductiestelsel Recap: Brain growth is nearly complete by the end of childhood. Muscle strength and coordination improve, and body form changes to a more adult form.
21.8.4 Adolescence: The transition to adulthood • Groeispurt o Slungeligheid o Tijdelijk verlies van coördinatie • Longen meer dan dubbel • Puberteit o Begin menstruaties o Natte droom o Hypothalamus secretie GnRH Recap: Adolescence is accompanied by a growth spurt and by maturation of the reproductive systems. Puberty begins when the hypothalamus matures and starts to secrete GnRH.
21.9 Aging takes place over time • most cells have an internal mechanism that limits the number of times they can divide • cumulative unrepaired cellular damage as a consequence of metabolic activity may limit the life of cells • aging may affect all organ systems because a decline in one system will affect other systems
21.9.1 What causes aging? • Fysiologische piek: 20 jaar • Oorzaken: hypotheses o Intern programma celdeling 50-90 succesvolle delingen Elke deling: verdwijnen telomeer • Op einde: geen telomeren meer vitale informatie wegeten • Kankercellen: uitzondering enzym dat telomeren aanmaakt Maar: ouder worden niet enkel daling celdeling maar ook in celfunctie o Schade aan cellen Door replicatie vrije radialen (bijproduct metabolisme) Alle schade bij elkaar opgeteld: te groot Evidence: minder calorieën langer leven o Lichaamsproces Schade aan 1 stelsel andere stelsel niet deftig functioneren Bv. immuunsysteem Recap: Aging is a complex process that is still poorly understood. It appears that most cells are limited in how many times they can divide, and that damage may accumulate in cells until they no linger function properly. At the whole-organism level, declines in function of one organ of system may eventually impair other organ systems.
21.9.2 Body systems age at different rates • Spieren & huid o Neemt af in vroege adulthood o Verlies spiercellen + minder diameter overblijvende cellen o Gewrichten: stijf & pijnlijk o Huid: dunner, minder elastisch, gerimpeld & minder zweetklieren • Cardiovasculair & ademhaling o Minder longcapaciteit o Hartwanden iets stijver o Bloedvaten: verlies elasticiteit hogere bloeddruk • Immuunsysteem o Minder T-cellen o B-cellen: minder activiteit o Slechter in herkenning eigen cellen • Zenuwstelsel o Delen niet verloren komen niet terug o Overgebleven neuronen: verbinden o Veranderingen in cellichaam van neuronen • Reproductief & endocrien stelsel o Menopauze Minder reactie op FSH & LH Minder secretie oestrogeen Hot flashes Minder vaginale smering Stemmingswisselingen Groter risico voor cardiovasculaire aandoeningen & osteoporose o Mannen: minder leefbaar sperma o Verlaging secretie groeihormoon • Spijsvertering & voeding o Sommige vitaminen niet efficiënt geabsorbeerd o Verlies van tanden o Ontgiftigende werking lever vermindert • Urinestelsel o Minder niermassa o Minder doorbloeding & filtratie o Lichte gevolgen Recap: The actual pattern of aging in various organ systems is well documented even if we don’t fully understand the underlying causes. All organs and organ systems decline in function with advancing age, though not necessarily at the same rate
21.9.3 Aging well • Beter oud worden: regelmatige beweging & gezonde voeding Even if the aging process cannot be stopped, it is certainly possible to improve human health and wellness throughout life. Regular exercise and healthy nutrition are important factors in aging well.
21.10 Death is the final transition • Death is a process. Death begins with the failure of one or more critical organs systems, leading to the failure of other organ systems and eventually to the death of all cells. • Orgaansysteem essentieel voor overleving op korte termijn faalt o Hersenen o Ademhalingsstelsel o Cardiovasculair stelsel • Probleem: niet altijd directe dood andere orgaansystemen • Keyword: onomkeerbaar! Recap: death is the termination of life. In a complex organism it is a process that can be gradual or brief. Death starts with the failure of one or more critical organ systems and ends ultimately with the inability to maintain an internal environment consistent with cellular life.
