PROCEDURE III (one student per group): REGULATION OF BREATHING: The effects of O2, CO2 and air.
A1. ROOM AIR (control-20 medium breaths without a bag)
$\frac{15}{2}$ total breaths, 2 min = 7.5 breaths per minute
A2. HYPERVENTILATION (DEEP BREATHS), 15 sec.
$\frac{4}{2}$ total breaths, 2 min = breaths per minute
B. pure OXYGEN (20 medium breaths from a bag)
$\frac{15}{2}$ total breaths, 2 min = 7.5 breaths per minute
C. 95% OXYGEN + 5% CO2 (20 medium breaths from a bag)
$\frac{14}{2}$ total breaths, 2 min = 7 breaths per minute
9. Which procedure above caused the subject to breathe slowest?
Explain why in terms of the brainstem respiratory center, chemoreceptors, and what they are most sensitive to.
10. Which procedure above caused the subject to breathe fastest?
Explain why in terms of the brainstem respiratory center, chemoreceptors, and what they are most sensitive to.
11. Why are some divers, swimmers, singers and wind instrument players able to hold their breaths so long? (Hint:
exercise and muscles of respiration....)
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