Which of the following will occur during even strenuous exercise ...

[penguins]

Which of the following will occur during even strenuous exercise in a normal healthy individual?
 
  a. Blood gases remain stable.
  b. The arterial PCO2 rises.
  c. The arterial pH falls.
  d. The arterial PO2 falls.

Question 2

Coexisting arterial hypoxemia, acidemia, and high PaCO2 (i.e., asphyxia) will have what effect on the peripheral chemoreceptors?
 
  a. There is a decreased drive to breathe.
  b. There is a maximally increased drive to breathe.
  c. There is insufficient information to make a determination.
  d. There is virtually no response.

[bob]

Answer to Question 1

ANS: A
Strenuous exercise increases carbon dioxide production and O2 consumption by as much as 20-fold. Ventilation normally keeps pace with CO2 production, keeping PaCO2, PaO2, and arteri-al pH constant. Because arterial blood gases do not change, elevated carbon dioxide or hypoxia does not stimulate ventilation in healthy individuals during exertion.

Answer to Question 2

ANS: B
Coexisting arterial hypoxemia, acidemia, and high PaCO2 (i.e., asphyxia) maximally stimulate the peripheral chemoreceptors.