Which of the following is indirectly responsible for ...

[arivle123]

Which of the following is indirectly responsible for minute-to-minute control of breathing?
 
  a. CO2 levels
  b. HCO3 levels
  c. Lactate levels
  d. Oxygen (O2) levels

Question 2

Which of the following causes hypoxic stimulation of the carotid bodies? 1. Large decrease in arterial PO2 2. Large decrease in O2 content 3. CO poisoning
 
  a. 1 only
  b. 1 and 2 only
  c. 1, 2, and 3
  d. 1 and 3 only

[EAN94]

Answer to Question 1

ANS: A
As the H+ ions in the CSF are generated in direct relation to the level of arterial PCO2, it is really the arterial PCO2 that (indirectly) controls primary minute-to-minute ventilation.

Answer to Question 2

ANS: A
When the PaO2 is low carotid body sensitivity to a given H+ increases; in this way hypoxemia increases ventilation for any given pH.