1. Pick up Norandro paper quizzes from front.
14 November 2008
Respiratory System # 3
Spirometry (brief intro)
Review of dead space
Gas exchange
Gas transport
Quick look at negative feedback control
Pick up Norandro paper quizzes from front.

2. Figure 13.06

3. Pulmonary Functions Test
Spirometry

4. Figure 13.18

5. Figure 13.18
Spirometry

6. Figure 13.19
inhale

7. Figure 13.19
exhale

8. Figure 13.20
CO2 production
O2 uptake

9. CO2 production
= Respiratory Quotient
O2 uptake
= 0.8 for proteins
= 0.7 for fat
= 1.0 for carbohydrates
=0.8 for mixed diet

10. What is affecting the amount of gas in the alveoli?
Gas exchange
All gases move by diffusion. Thus limited by:
Surface area
Distance
Concentration gradient
In the lung, gases must move from air to water and vice versa. The amount is directly proportional to
Solubility
Temperature
Pressure gradient
What is affecting the amount of gas in the alveoli?

11. Pathological limitations to diffusion

12. Gas Laws Dalton’s Law Henry’s Law
Total pressure = sum of partial pressures
PATM = P N2 + P O2 + P CO2
100% = 79% + 21% + <1%
P O2 = 0.21 x 760mmHg = 160
Partial pressure of Oxygen in atmosphere at sea level is 160 mmHg
N2 is physiologically inert; ignore
Gases dissolve in liquids in proportion to their partial pressure in the air in contact with that liquid
air
P O2 =160 mmHg
blood
P O2 =160 mmHg

13. Ventilation by Bulk Flow
Figure 13.21
Ventilation by Bulk Flow
Pulmonary Venous blood is equivalent to Systemic Arterial blood.
Alveolar to arterial gradient is due to ventilation/perfusion inequality.
Gas exchange
For negative feedback, 1 What is the stimulus? 2 Where should the receptors be located?
Gas exchange
Gradient for CO2 is only 6 mmHg;
CO2 is more soluble and permeable than O2

14. Peripheral Chemoreceptors
Figure 13.33
Peripheral Chemoreceptors
Carotid bodies (not carotid sinuses which are baroreceptors)
Aortic bodies (not aortic arch baroreceptors)
Central Chemoreceptors in medulla
To ponder: Why should there be three sets of chemoreceptors?

15. Table 13.10

16. Figure 13.36

17. Figure 13.38

18. Figure 13.34