Which of the following is true of the heart rate change during exercise?
A) the increase in HR is due only to withdrawal of PNS influence.
B) the increase in HR is due only to increasing SNS influence.
C) the increase in HR is due only to PNS withdrawal followed by increasing SNS influence.
D) the increase in HR is due to a spontaneous increase in SA node activity.

Question

Quizplus · Accepted Answer

During exercise, the initial increase in heart rate is due to PNS withdrawal, followed by an increasing influence of the SNS. Therefore, option C is the correct answer. Option A is incorrect because PNS withdrawal is not the only factor responsible for the increase in heart rate. Option B is incorrect because the increase in heart rate is not solely due to SNS influence. Option D is incorrect because the increase in heart rate is not spontaneous and is a result of neural and hormonal stimulation.

Which of the Following Is True of the Heart Rate