Ascending pathways of brainstem Flashcards
3 portions of GSA inut for trigeminal sensory nuclear complex
mesencephelic nucleus
principal trigeminal or main nucleus
spinal trigeminal nucleus
spinal ncuelus of trigemina
nucleus oralis - mouth
nucleus interpolaris - mouth
nucleus caudalis
opthalmic
V(1)
maxillary
V(2)
madibular
V(3)
Main sensory nucleus
Pons
vibrotactile discrimination
chief sensory nucleus
like nucleus gracilis or cuneatus
Spinal trigeminal
medulla
pain, temperature, down to cervical cored
nucleus causalis
Mesencephalic
midbrain
proprioceptive
psuedounipolar
ventral trigeminotholamic (spinotrigeminal) tract transmits
nociceptive info of head
all trigeminal nerves come into
pons
VentralTrigeminothalamictract type of ingo
pain temp
VentralTrigeminothalamictract point of origin and receptors
free nerve ending (trpV channels) skin, viscera and muscles
VentralTrigeminothalamictract cell bodies
trigeminal/semilunar/gasserian nucleus
VentralTrigeminothalamictract enters and travels
Pons, descends to spinal trigeminal nucleusof medulla via the spinal trigeminal tract
VentralTrigeminothalamictract decussates
Internal arcuatefibers ventral to spinal trigeminal nucleus in medulla (travels with anterolateralsystem)
VentralTrigeminothalamictract first synapes
spinal trigeminal nucleus (somatotopic organization)
VentralTrigeminothalamictract second synapse
ventral posterior medial nucleus (VPM) of thalamus
VentralTrigeminothalamictract final destination
Primary somatosensory cortex (via internal capsule and corona radiate)
orientation of trigeminal fibers in spinal trigeminal nuclei
lateral to mideal V123
order of trigeminal fibers in vpm
v321 medial to lateral
The Spinal Trigeminal Tract also carries fibers from 3 additional cranial nerves
•CN VII –Ear (small portion) •CN IX –Ext. auditory meatus –Back of ear •CN X –External ear
trigeminal neuralgia
- “tic douloureux”
- Most common in maxillary div
- Vascular compression
- Right side more commonly affected
hyperctivity of nociocerptor neurons feeding into spinal trigeminal nucleus
nociceptive input of meninges
diff. branches of V
don’t feel pain in brain just dura so most of the pain is reffered pain
lateral aspects goes to maxillary and mandibular the rest goes to the eyes
The trigeminocardiacreflex can be carried via the spinotrigeminaltract
–Duringneurosurgery, complication from massive parasympatheticresponse:
Heart Rate
Blood Pressure
Respiration Rate
cold water on face, diving reflex, worse in childre
MSN/ML and Dorsal Trigeminothalamictract type of info
Tactile discrimination, Point of origin, receptors involved: Meissner’s corpuscles, merkel’sdisks, paciniancorpuscles, ruffini’sendings
MSN/ML and Dorsal Trigeminothalamictract cell bodies
trigeminal/semilunar/gasserian
MSN/ML and Dorsal Trigeminothalamictract first synapse
main sensory nucleus
MSN/ML and Dorsal Trigeminothalamictract enters and travels
pons, ascend contralaterally (for face) and ipsilaterally (for oral cavity)
MSN/ML and Dorsal Trigeminothalamictract decussates
in pons, ascends with medial lemniscus
MSN/ML and Dorsal Trigeminothalamictract second synapse
ventral posterior medial nucleus (VPM) of thalamus
MSN/ML and Dorsal Trigeminothalamictract final destinatino
primary somatosensory cortex (via interal capsul and corona radiata
basic touch info of the head ascends
bilaterally in 2 pathways
oral cavity ascends
ipsilaterally
head ascends
contralaterally
Trigeminocerebellar tract type of info
unconscious proprception of head
Trigeminocerebellar tract point of origin and receptors
muscle spindles gto in muscles joints and tendons
Trigeminocerebellar tract cell bodies
mesencephalic nucleus
Trigeminocerebellar tract first synapse
cerebellum
Trigeminocerebellar tract enters and travels
enters pons ascend to mesencephalic nucelus
Trigeminocerebellar tract decussates
unknown
Trigeminocerebellar tract second synapse
vermis of cerebellum via inferior cerebellar peduncle
Trigeminocerebellar tract final destination
deep cerebellar nuclei (via purkinje cells)
proprioceptive input enters the brain at the pons and ascends to
midbrain
From the Mes. NucV:
- Cerebellum (Proprioceptive)
- Vestibular nuclei (proprioceptive, reflex)
- Reticular formation (change behavioral state)
- Motor nucleus of V (Jaw-jerk reflex)
- Facial motor nucleus (Primary-gaze frontalisreflex)
proprioceptive reflex arc to face important for
1) Important in preventing Ptosis
2) Important for raising eyebrows
voluntary eye opening
when voluntary open eyes
no muscle spindles
specialized mechanoreceptor(acts like spindle in wheelers muscle above eyelid
wheelers muscle sends axons back to
mesocephalic nucleus of trigeminal nerve when we voluntarily open eyre
through this same axon loops around and goes to occulomotor nucleus and activates levator palpebrae to open eye more
other place it goes is facial motor nucleus to activated frontalis muscle
yayoi-derived trait
eyebrows raised in primary gaze
from asia
no superior palpebral fold
for retaining heat
primary gaze affected so they have more frontalis and a higher arch above eye
ligament keeps eyes a little closed
jomon-derived trait
eyebrows not raised in primary gaze
western eye like native americans
have palperbral fold
lateral meduallry (wallenbergs) syndrom
•Stroke of the PICAleads to, (among other symptoms)
–Ipsilateralloss of Pain/Temp in the face
–Contralateralloss of Pain/Temp in the body
–Horner’s Syndrome