Trigeminal Pathways (Stephens) Flashcards
central processes of pseudounipolar neurons in the trigeminal ganglion enter brainstem and these fibers ascend only in the short ascending root of V and terminate _____ these fibers convey what
main sensory nucleus of V
-precise discriminative tactile info from the face
fibers adjacent to ascending root course in the ______ which conveys ______ info to main sensory nucleus
mesencephalic tract of V
-proprioception
1/2 of fibers that descend only in what tract and terminate where
-convey what fibers
descending root (tract) of V
subnucleus caudalis of descending nucleus of V
-convey pain and temp info from the face
the descending root of V is continuous with what
dorsolateral fasciculus of lissaeur in spinal cord
where do the secondaries go in precise tactile pathway
from main sensory nucleus:
some cross and go up trigeminal lemniscus and some stay ipsilateral in dorsal trigeminal thalamic tract
where do secondary neurons in pain/temp path come from and go
come from subnucleus caudalis, cross midline and ascend as trigeminal lemniscus
where do crude tactile fibers go
ascend to main sensory nucleus
descend to subnucleus rostralis and interpolaris
-hard to lose crude tactile to face
main sensory nucleus receives what fibers
precise tactile, crude tactile, and proprioceptive info from face
descending spinal nucleus of V 3 parts and what terminates here (what info)
subnucleus:
rostralis: tactile info
interpolaris: info from peripheral region of face
caudalis: pain and temperature info from anterior 1/2 of head
-
what is the only nucleus in the CNS comprised of pseudounipolar neurons?
mesencephalic nucleus of V
what info does mesencephalic nucleus convey
proprioceptive and pressure info from muscles of head and oral region
root of fibers to mesencephalic nucleus
peripheral process of pseudounipolar neuron courses with mandibular nerve through trigeminal ganglion and enters brainstem with trigeminal nerve, process ascends towards the mesencephalic nucleus in mesencephalic root of V
where does the central process of the mesencephalic nucleus terminate
main sensory nucleus, conscious awareness facial and oral proprioception via TL and DCTT
where do other central processes of mesencephalic nucleus terminate
directly upon alpha motor neuron of the trigeminal motor nucleus, this monosynaptic circuit forms jaw-jerk relfex
what are the only things that project to the cerebellum
subnuclei rostralis and interpolairs
path of subnuclei to cerebellum
-what info
subnuclei R/I project trigeminocerebellar fibers to anterior vermis via ipsilateral inferior cerebellar peduncle
-crude tactile info from head
a moderate number of secondary neurons in main sensory nucleus project to anterior vermis of cerebellum via what these fibers convey what
superior cerebellar peduncle
-fibers convey precise tactile and proprioceptive info from head to cerebellum
unilateral lesion of trigeminal nerve results in what
anesthesia and loss gen sesations trigem dermatomes
loss jaw jerk reflex
atrophy of muscles of mastication
loss ipsilateral and consensual corneal reflex
alternating analgesia
brainstem lesion in upper medulla may destroy primary fibers in descending tract of V and secondary fibers in SL
- ipsilateral hemianalgesia of face
- contralateral hemianalgesia of the body
alternating trigeminal hemiplegia
unilateral destruction of trigeminal n and corticospinal tract in pons
- ipsilateral trigeminal anesthesia and paralysis
- contralateral spastic hemiplegia
what is trigeminal neuralgia
trigger zone in head may initiate epileptic like discharge from subnucleus caudalis
-intractable lacerating facial pain which follows distribution of affected division of trigeminal nerve
