Which type of muscles does the nucleus ambiguus control?

Which type of muscles does the nucleus ambiguus control?

• A. Visceral muscles
• B. Skeletal muscles
• C. Cardiac muscles
• D. Smooth muscles

Answer: (B)

This question tests which muscle type receives motor control from the nucleus ambiguus. The nucleus ambiguus contains somatic motor neurons that innervate skeletal muscles derived from the pharyngeal arches, specifically the muscles of the soft palate, pharynx, and larynx via the glossopharyngeal and vagus nerves. These are striated, voluntary muscles, not smooth or cardiac muscles. In contrast, cardiac and smooth muscles are targets of autonomic (parasympathetic and sympathetic) pathways, coming from other brainstem and spinal centers, not this nucleus. So the nucleus ambiguus primarily governs skeletal muscles of the throat and voice box.

This question tests which muscle type receives motor control from the nucleus ambiguus. The nucleus ambiguus contains somatic motor neurons that innervate skeletal muscles derived from the pharyngeal arches, specifically the muscles of the soft palate, pharynx, and larynx via the glossopharyngeal and vagus nerves. These are striated, voluntary muscles, not smooth or cardiac muscles. In contrast, cardiac and smooth muscles are targets of autonomic (parasympathetic and sympathetic) pathways, coming from other brainstem and spinal centers, not this nucleus. So the nucleus ambiguus primarily governs skeletal muscles of the throat and voice box.