[UW Anatomy | Contents]

Function:
Pain and temperature from the ipsi. side of the face, teeth, ant. two-thirds of tongue, palate.

Pathway:
Central processes of cells in the trigeminal ganglion enter the pons and descend in the spinal tract V; these axons end in the caudal spinal nucleus V in the medulla. Axons of neurons in the caudal spinal nucleus V cross the midline and ascend as the trigeminothalamic tract (T.T.T.) to reach the ventral posteromedial nucleus (V.P.M.) of the thalamus. V.P.M. neurons project to areas 3,1,2 of somatosensory cortex.

Deficits:
Lesion in the caudal spinal tract and nucleus V results in ipsi. deficits in pain and temperature from the face, teeth and ant. two-thirds of tongue and palate. Lesion of the T.T.T. results in contra. deficits of same modalities.

Other Note:
Central processes of cells in geniculate ganglion VII, superior ganglion IX and superior ganglion X also enter spinal tract V and end in the caudal spinal nucleus V. Pathways convey pain and temperature from the "ear", pharynx, larynx and upper esophagus.