1. Anatomy & Physiology II
Unit Six

2. Major Atmospheric Gases
Nitrogen - N2 - 78%
Oxygen - O2 - 21%
Carbon dioxide - CO %

3. Dalton’s Law
The total pressure of a gas mixture is the sum of the partial pressures that each of the gases in the mixture would exert independently

4. Respiration Respiration is divided into three phases: + ventilation
+ external respiration
+ internal respiration

5. Partial Pressures and the Movement of O2 & CO2

6. Blood Gas Transportation
Oxygen transport:
* hemoglobin on RBCs %
* dissolved in plasma - 1.5%
Carbon dioxide transport:
* hemoglobin on RBCs - 20%
* dissolved in plasma - 10%
* converted to HCO %

7. Blood Gas Transportation
Hemoglobin and
Blood Gas Transportation

8. Blood Gas Transportation
Hemoglobin and
Blood Gas Transportation
Formation of oxyhemoglobin
HHb + O2 HbO2 + H+
Carbaminohemoglobin formation
CO2 + Hb HbCO2

9. Blood Gas Transportation
Hemoglobin and
Blood Gas Transportation

10. Blood Gas Transportation
Hemoglobin and
Blood Gas Transportation

11. The Oxyhemoglobin
Dissociation Curve

12. Oxyhemoglobin and the Unloading Oxygen
pH and temperature will affect the rate and amount of HbO2 dissociation
The Bohr effect - the increase in HbO2 dissociation in response to low pH

13. Oxyhemoglobin and the Unloading Oxygen
The decrease in pH is the result of glucose metabolism in cells
The metabolism results in H+ and CO2 being passed into the capillaries, decreasing the pH and increasing the Pco2

14. Oxyhemoglobin and the Unloading Oxygen
HbO2 is induced to give off O2 for four reasons:
► ambient Po2
► temperature increase
► pH decrease
► BPG (biphosphoglycerate)

15. The Effects of Temperature and pH
The Oxyhemoglobin
Dissociation Curve
The Effects of Temperature and pH

16. Neural Control of Respiration
Pontine respiratory center
Dorsal respiratory group
Ventral respiratory group

17. Neural Control of Respiration

18. Neural Control of Respiration

19. Neural Control of Respiration
Since O2 is carried in such high reserves and saturation, it has little effect on the rate of ventilation
CO2 concentration and pH do significantly change and have an immediate effect on ventilation

20. Neural Control of Respiration
Therefore, ventilation functions to maintain Pco2 within its homeostatic range