This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroanatomy, Subject name: Anatomy
Nucleus ambiguus is composed of: 
Select and explain. 
A. 7,9,10 cranial nerve nucleus, B. 7,9,11 cranial nerve nucleus, C. 9,10,11 cranial nerve nucleus, D. 7,10,11 cranial nerve nucleus
C: 9,10,11 cranial nerve nucleus
Answer: C: 9,10,11 cranial nerve nucleus 
Explanation: Ans. C. 9,10,11 cranial nerve nucleusCells in nucleus ambiguus contain motor neurons associated with three cranial nerves (rostral pole = C.N. IX = glossopharyngeal; middle part = C.N. X = vagus; caudal pole = C.N. XI = spino accessory). Axons arising from nucleus ambiguus pass laterally and slightly ventrally to exit the medulla just dorsal to the inferior olive. These axons then course with the three cranial nerves IX (glossopharyngeal), X (vagus) and XI (spino accessory) to innervate the striated muscles of the soft palate, pharynx, larynx, and upper part of the esophagus.