1 / 22

Circulation and gas exchange

Circulation and gas exchange. Evolution. Open circulatory system Insects arthropods No difference between blood and interstitial fluid = hemolymph Gas exchange: rate of transfer proportional to surface area. Evolution. Fish: 1 atria 1 ventricle Heart to gills, gills to body

yoshe
Télécharger la présentation

Circulation and gas exchange

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Circulation and gas exchange

  2. Evolution • Open circulatory system • Insects • arthropods • No difference between blood and interstitial fluid = hemolymph • Gas exchange: rate of transfer proportional to surface area.

  3. Evolution • Fish: 1 atria 1 ventricle • Heart to gills, gills to body • Water is dense with little O2 per volume • Gills: countercurrent exchange • Gas exchange (blood flows one way while outside water going in opposite direction) • Thermo regulation • kidney

  4. Insects: system of tracheal tubes, gas exchange throughout • Amphibians: 3 chambered heart • Reptiles: double circulation • Pulmonary circuit + systemic circulation • NO mixing of oxygenated and deox blood

  5. Our system • 4 chambered heart • Double circulation: • Right side: pulmonary • Left side: systemic

  6. Rate of diffusion proportional to surface area • Protists: occurs over entire surface (cnid. Flats) • Earthworms and amphibs: across moist skin • Gills: warmer, saltier less O2 • Insects: tracheal tubes: branch out to do exchange with all body parts. Open circ. System NOT involved in transport: O2 CO2

  7. Lungs • Reptiles • Birds • Mammals • Lungs not in contact with all cells of body • Gap bridged by circulatory system

  8. Pharynx: food and air, epiglottis • Larynx: vocal cords (air only) • Trachea: cartilage rings • Bronchi: 2. Right is more horizontal. More stuff • Bronchioles • Alveoli: air sacs and capillaries. 1 cell thick

  9. Breathing • Diaphragm: negative pressure • Tidal volume: air in and out with reg breath • Residual volume: air that remains in alveoli and tubes after you breath out. • Us: air travels down 1 way street. • Birds: better: are travels through… no dead ends

  10. Controls of breathing • Pons • Medulla • Sensors in aorta

  11. Lungs: only site of gas exchange: need circulatory system • Breath: negative pressure breathing • Partial pressure: gas diffuses from its own high partial press. To low (press. Just this 1 gas contributes to the press. Of air (a mix))

  12. O2 does NOT dissolve easily in blood • Need HEMOGLOBIN to hold the O2 • Bohr shift: increase affinity for heme to O2 when pH is elevated (by high CO2) • Myoglobin: protein that binds and stores O2 in muscles

  13. Blood • Blood: • Connective tissue with liquid matrix • plasma and 3 types cells • Leukocytes, erythrocytes, platelets • 5L • Kidney maintains plasma (90% water) • All blood cells from pluripotent cells in bone marrow

  14. homeostasis • If low O2 • kidneys: erythropoietin: increase production of erythrocytes

  15. Disease • Blood pressure: 2 factors: • Cardiac output and peripheral resistance • Atherosclerosis: • Plaques/ hardening of arteries (cholesterol, LDL) • Hypertension: over time, elasticity of vessels • Heart attack: MI, coronary arteries • Stroke: blocked vessel

  16. Control blood flow to capillaries: • Pre-capillary sphincter • Smooth muscle: constrict blood flow to that cap. • Lymphatic system: lymph drained out of circulating blood. Same • Lymph nodes: lots of WBC

  17. Pathway of blood • Right atria (deox blood) • Right ventricle • Pulmonary artery • Lungs : pulmonary circulation • Pulmonary vein • Left atria • Left ventricle • Aorta: systemic circulation

  18. Atria: thinner walls • Ventricles: stronger • Valves: heart sounds are the closing of valves • 2 AV (atria to ventricle) • 2 semilunar. From ventricle out of heart • Pulmonary artery and veins : ONLY Time and artery carries deox and a vein carries oxygenated blood

  19. heart • Gap junctions: form communication • SA NODE: local control of rate. Special tissue in right atria

  20. Arteries: higher pressure. From heart • Veins: pressure from move skeletal muscle.

  21. Vocabulary • Systole • Diastole • SA node

More Related