Nucleus ambiguus is not associated with which cranial nerve: March 2010, March 2013

Ans. D: XIINucleus AmbiguusFunction:Motor innervation of ipsilateral muscles of the soft palate, pharynx, larynx and upper esophagus.Pathway:Axons of motor neurons in the nucleus ambiguus course with three cranial nerves: C.N. IX (glossopharyngeal), C.N. X (vagus), C.N. XI (rostral or cranial poion of spinoaccessory) to innervate striated muscles of the soft palate, pharynx, larynx and upper esophagus.Deficits:Lesion of nucleus ambiguus results in atrophy (lower motor neuron) and paralysis of innervated muscles, producing nasal speech, dysphagia, dysphonia, and detion of the uvula toward the opposite side (strong side).No affection of the Sternocleidomastoid or Trapezius. These muscles are innervated by cells in the rostral spinal cord (caudal poion C.N. XI).