This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Taste fibres are relayed to which of the following structure? 
Select and explain. 
A. Nucleus of fifth nerve, B. Tractus solitarius, C. Nucleus ambiguus, D. Red nucleus
B: Tractus solitarius
Answer: B: Tractus solitarius 
Explanation: Nucleus solitarius is an elongated sensory nucleus in the medulla that receives axons from cranial nerves VII, IX, and X. The rostral pa of this nucleus is called gustatory nucleus and it conveys information about taste and visceral sensations. Fibers from this nucleus ascend to ventroposterior nucleus (VPM) in the thalamus and project to the coical area for taste (area 43, located near the operculum). Nucleus ambiguus gives rise to the branchial efferent axons in nerves IX and X. It controls swallowing and vocalization. Superior salivatory nucleus is located just rostral to the dorsal motor nucleus. This nucleus controls salivary secretion and lacrimation. Ref: Waxman S.G. (2010). Chapter 7. The Brain Stem and Cerebellum. In S.G. Waxman (Ed), Clinical Neuroanatomy, 26e.