Trigeminal Flashcards
Merkel and Ruffini are
slow adapting
Pancinian and Meisner are
rapidly adapting
What are our warming receptors in face
C fibers
What are the cooling receptors in face
A-delta
Where are the cell bodies of face located (touch/proprio)
trigeminal ganglion
What are the peripheral processes of the TG (touch/proprio)?
CN V = trigeminal nerve
Where does the trigeminal N head from the trigeminal ganglion (touch/proprio)
enter brainsteom at ventrolateral pons
Where are the second order neurons for Trigem system located (touch/proprio)
Main sensory nucleus or Chief sensory nucleus V
What is the ascending pathway from second order neurons of Trigem after leaves Cheif sensory nucleus (touch/proprio)
Medial lemniscus or Trigeminal Lemniscus
Destination of the ascending pathway for trigeminal system (touch/proprio)
VPM
Primary afferent cell body location for pain/temp of face
Trigem ganglion
Central processes of Trigem system for pain and temp
Spinal tract
Second order neurons for face (pain/temp)
Spinal nucleus (caudal nucleus)
Ascending pathway for pain/temp on face
Trigeminothalmanic tract
Destination of the ascending pathwaay for pain/temp afferents of face
VPM and others
Both pain and fine touch from face end up in
VPM
Crude touch from face takes a different path by:
entering pons and descending down spinothalmic tract w/out synapsing
Where do crude touch for face synapse?
on the spinal nuclues after descending from pons and CROSSES OVER
Where do crude touch fibers from face cross over?
in caudal medulla (other fine touch do so in pons)
What is special about oral cavity sensory info
follows same general pathway by entering Trigem ganglion–> principle sensory nucleus of V in pons BUT some cross over and acsend up Dorsal trigeminal tract while others ascend up dorsal trigem on same side
Oral cavity representation is:
bilateral
Somatotopy of VPM
Tongue = medial
oral cavity
Face it lateral
Fine touch uses this for 2nd order neurons:
Pain uses this path for 2nd order neurons:
Trigeminal lemniscus
Trigeminothalmic
Fine touch crosses contralateral at:
Pain crosses contralateral at:
level of pons
level of caudal medulla after descending
Touch Second order neurons are located :
Pain second order neurons located:
Chief sensory nucleus in pons
Spinal nuclues in caudal medulla
Both touch and pain uses this for housing first order neuron cell bodies
trigeminal ganglion
Fine touch uses this for pirmary afferents (central processes)
Pain uses this for primary afferents (central Processes)
entering trigeminal fibers
spinal tract
Recurrent episodes for seconds to minutes
a. Neuralgia = pain along a course of nerve
b. Recurrent espisode of excruciating pain lasting seconds/mins
c. Occurs in any or many: ear/eye/lips/nose/scalp/forehead/teeth/jaw
d. regions of V2/V3 territory
e. Provoked by chewing, shaving, brushing teeth, touching trigger pts
Unknown cause but it is NEUROPATHIC pain
Trigeminal neuralgia or ‘tic douloureux’
TX for tic douloreux
TX: carbamazepin sometimes antidepressents
Tx for TMJ
NSAIDS or mouthguard
Fibers carrying fine touch from body and face enter;
medial lemniscus
trigeminal lemniscus
AT different levels
Body fibers for medial lemniscus enter at level of
fine touch
caudal medulla
Face fibres for trigeminal lemniscus enter at level of
fine touch
pons
When you think leminscus think:
fine touch
Above this level medial lemniscus and trigeminial lemniscus run together
above pons
Fibers carrying pain/temp from body enter as
from face enter as
anterolateral tracts (body) trigeminothalmic tracts (face)
Body fibers for pain enter where
all along spinal cord
face pain fibers enter in
from cervical cord to caudal medulla (where spinal nucleus V located)
At what level to anterolateral and trigeminothalmic tracts run together
rostral level
