Point
3
Intro
Point: 3. Spinal Nucleus and Tract of C.N. V
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.