Question

If a man could learn to stop his heartbeat at will, he must have control over his

• A. Central nervous system
• B. Peripheral nervous system
• C. Autonomic nervous system
• D. Cranial nerves

Answer 1

Answer: (C)

Autonomic nervous system

The central nervous system includes brain and spinal cord. It integrates and stores the sensory information from external and internal sense organs and commands different organs to respond accordingly.

Peripheral nervous system lies outside the central nervous system. It serves to carry the sensory information from external sensory receptors to CNS and motor signals from CNS to skeletal muscles via its somatic division (the voluntary actions). The autonomic division of peripheral nervous system controls the cardiac and smooth muscles and glands, thereby the functioning of internal organs, without our conscious control (the involuntary actions). The autonomic nervous system controls the heartbeat rate via cardioregulatory centre in the medulla oblongata. The emergency conditions activate the sympathetic motor nerve and make the adrenal medulla release epinephrine and norepinephrine which in turn increase the heartbeat rate. On the other hand, vagus nerve conducts the parasympathetic motor impulses which in turn slow down the heartbeat rate by the effect of acetylcholine. Thus, to control heartbeat, a man should have control over its autonomic nervous system.

The 12 pairs of cranial nerves are part of the peripheral nervous system and are mostly concentrated in head, neck and facial region of the body (vagus nerve X being the part of autonomous division serves as an exception).

Hence, the correct answer is option C.