Question

At the onset of exercise Madeline's heart rate increases from 60 bpm to 95 bpm. What causes this increase in heart rate?

Select one:

a. Stimulation of the heart from the sympathetic nervous system

b. Withdrawal of parasympathetic nervous system stimulation from the heart

c. Stimulation of the heart by the somatic nervous system

d. Both a and b

e. None of the above

Answer 1

Correct answer is option A and option B both

during exercise, the sympathetic system is activated. Sympathetic system is responsible for' Flight and fight ' action of body. It means it prepares our body to deal with adverse conditions.

During exercise, the oxygen and nutrients demand of body increases. To supply more oxygen, heart has to perform more work . This is the reason why heart rate increases.

The parasympathetic system works opposite to sympathetic system. It tends to make body in a position of rest. It decrease heart rate. Thus to increase heart rate, there has to be withdrawal of parasympathetic nervous system so that heart rate can increase.

Somatic nervous system only innervates the skeletal muscles. Since heart muscles are not skeletal in nature, there is no role of somatic nervous system during exercise.