Question

What structure(s) in the heart is/are innervated by cranial nerve x?

a. Av node only
b. SA node only
c. Av node and sa node

Answer 1

Av node and SA node.

Step-by-step explanation:

Cranial nerves are the nerves that are directly emerges from the brain. The tenth cranial nerve of the nervous system is the vagus nerve.

The left vagus nerve of the brain innervates the atrioventricular or AV nodes of the heart. The right vagus nerve or cranial nerve X innervates the sinoatrial or SA node of the heart. Hence, the vagus nerve innervates both the AV node and SA node of the heart.

Thus, the correct answer is option (c).