Question

which cranial nerve controls several essential bodily functions, among them the heart rate and respiratory rate?
a) trigeminal
b) vagus
c) hypoglossal
d) accessory

Explanation:

The vagus nerve (cranial nerve X) regulates autonomic functions including heart rate and respiratory rate. The trigeminal nerve controls facial sensation/movement, hypoglossal controls tongue movement, and accessory controls neck muscles—none of these manage heart or respiratory rates.

Answer:

b) Vagus