1 / 26

Carriage of respiratory Gases

Carriage of respiratory Gases. By Y Stock. Objectives. You should be able to: Describe the structure of erythrocytes. Describe the role of respiratory pigments. Understand and interpret dissociation curves. WWW.NIM.NIH.GOV. Red blood cells. Biconcave discs 8 micrometers diameter

shaeleigh-aguirre
Download Presentation

Carriage of respiratory Gases

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. Carriage of respiratory Gases By Y Stock

  2. Objectives • You should be able to: • Describe the structure of erythrocytes. • Describe the role of respiratory pigments. • Understand and interpret dissociation curves.

  3. WWW.NIM.NIH.GOV

  4. Red blood cells • Biconcave discs • 8 micrometers diameter • No nucleus • Made in bone marrow • Destroyed by liver/spleen

  5. Function: To carry oxygen and carbon dioxide • Adaptions: • Shape gives a large surface area, encouraging diffusion • Full of haemoglobin

  6. www.astrographics.com/.../Display/GP2120.jpg

  7. Haemoglobin www.chemsoc.org/.../LearnNet/cfb/images/13A.jpg

  8. Haemoglobin • Consists of 4 polypeptide chains, each with an iron containing haem group. • Each haem group combines with an oxygen molecule

  9. Haemoglobin+oxygen=oxyhaemoglobin • Hb + 4O2 = HbO8 • Reversible reaction

  10. www.scientific-art.com/.../Haemoglobin.gif

  11. High partial pressure oxygen Lungs Oxyhaemoglobin formed Low partial pressure oxygen Active tissues Oxyhaemoglobin breaks down Oxygen released Hb + 4O2 = HbO8

  12. Oxygen dissociation curves • Found by exposing haemoglobin to air mixtures of varying oxygen partial pressures and determining its % saturation.

  13. www.jcu.edu/biology/RESPS.JPG

  14. S shaped curve • Over the steep section a small fall in Oxygen partial pressure causes a sizeable drop in % saturation.

  15. The curve shows that: • at relatively low oxygen concentrations there is uncombined haemoglobin in the blood and little or no oxyhaemoglobin, e.g. in body tissue • at relatively high oxygen concentrations there is little or no uncombined haemoglobin in the blood; it is in the form of oxyhaemoglobin, e.g. in the lungs.

  16. Effect of increased carbon dioxide

  17. Bohr Effect • Curve shifted to right • Increased CO2causes oxyhaemoglobin to unload some of its oxygen.

  18. www.coheadquarters.com/Bohr1.gif

  19. Fate of carbon dioxide • 7-10% dissolves in plasma • 20-30% in red cells as carbaminohaemoglobin (binds to amino acids) • 60-70% converted to bicarbonate in plasma

  20. Conversion to bicarbonate • Carbon dioxide diffuses into red cells • Enzyme:carbonic anhydrase • CO2 + H2O = H2CO3

  21. This dissociates • H2CO3 = H+ + HCO3- • HCO3- diffuses into plasma • H+ combine with oxyhaemoglobin forming haemoglobinic acid. • H+ + HbO2 = HHB + O2 • Oxygen displaced. • Haemoglobin buffering pH changes

  22. www.colprado.edu/.../image/figure13g.jpg

  23. Myoglobin -Curve shifted to left • Myoglobin binds more tightly to oxygen. • Oxygen only given up at very low PO2

  24. Images.encarta,msn.com/…/cha/00076b5f.gif

  25. Quiz Haemoglobin quiz image search RSC

More Related