Point 11


Intro

Pathway

Deficit

Note

Clinical

Taste

Overview

Problems


Contents

Anatomy

 

 

Point: 11. Nucleus and Tractus Solitarius

Function:
Nucleus receives input from the viscera and taste buds (viscerosensory).

Pathway:
Caudal portion of nucleus solitarius receives input from viscera (cell bodies in the inferior ganglion X) and from the carotid sinus (baroreceptors; cells in the inferior ganglion IX). Central processes travel in caudal fasciculus solitarius and synapse in caudal nucleus solitarius. Cells in caudal nucleus solitarius project to the dorsal motor nucleus X and other parts of the brainstem and spinal cord involved in visceral reflexes (lateral cell column in spinal cord). Rostral part solitary complex receives TASTE input from central processes of cells in the geniculate ganglion VII (taste buds on ant. 2/3 tongue), inferior ganglion IX (taste buds on post. 1/3 of tongue) and inferior ganglion X (scattered taste buds on the epiglottis). Axons arising from cells in the rostral nucleus solitarius comprise the solitariothalamic tract (S.T.T.). The S.T.T. is an UNCROSSED pathway that terminates in the V.P.M. of the thalamus. Cells in the V.P.M. project to somatosensory cortex (areas 3,1,2).

Deficits:
Lesion of rostral portion of nucleus and tractus solitarius is the most important. Such lesions result in the loss of taste from the IPSI. one half of the tongue. Lesion of the S.T.T. also results in the loss of taste from the IPSI. one-half of the tongue.

Other Note:
NO PROBLEMS WITH PAIN AND TEMPERATURE FROM THE TONGUE.