GROSS ANATOMY

Detailed explanation-1: -Motor fibers from the nucleus ambiguus innervate the stylopharyngeus muscle and participate in the innervation of the pharyngeal muscles for swallowing.

Detailed explanation-2: -Stylopharyngeus muscle: A long muscle that runs down part of your throat. CN IX connects to this muscle to lift the voice box (larynx) and nearby throat (pharynx). This makes it possible to swallow.

Detailed explanation-3: -All the muscles of the pharynx receive innervation from the tenth cranial nerve (vagus nerve) except the stylopharyngeus, which is innervated by the ninth cranial nerve (glossopharyngeal nerve).

Detailed explanation-4: -This component of CN IX innervates the baroreceptors of the carotid sinus and chemoreceptors of the carotid body.

Detailed explanation-5: -Innervation. The stylopharyngeus is the only muscle of the pharynx innervated by the glossopharyngeal nerve (CN IX) (all others being instead innervated by the vagus nerve (CN X)) by special visceral motor neurons with their cell bodies in the rostral part of the nucleus ambiguus.