The nucleus ambiguus innervates muscles to mediate which function?

The nucleus ambiguus innervates muscles to mediate which function?

• A. Swallowing and phonation
• B. Eye movement
• C. Tongue movement
• D. Facial expression

Answer: (A)

The nucleus ambiguus is the brainstem motor nucleus that sends impulses to the pharyngeal and laryngeal muscles via the glossopharyngeal and vagus nerves. This makes swallowing and voice (phonation) possible, since the pharyngeal constrictors, soft palate muscles, and intrinsic laryngeal muscles rely on these pathways. It does not control the extraocular muscles needed for eye movements, the hypoglossal-controlled tongue muscles, or the facial nucleus that governs facial expression. So swallowing and phonation are the functions mediated by this nucleus.

The nucleus ambiguus is the brainstem motor nucleus that sends impulses to the pharyngeal and laryngeal muscles via the glossopharyngeal and vagus nerves. This makes swallowing and voice (phonation) possible, since the pharyngeal constrictors, soft palate muscles, and intrinsic laryngeal muscles rely on these pathways. It does not control the extraocular muscles needed for eye movements, the hypoglossal-controlled tongue muscles, or the facial nucleus that governs facial expression. So swallowing and phonation are the functions mediated by this nucleus.