pons 2 Flashcards
Central Innervation of CN 5
Bilateral but mostly crossed pattern. Initial one sided weakness if lesion, but recovers due to bilateral.
CN 5 motor root
Carries SVE fibers for Innervation of muscles of mastication, tensor tympani, tensor palitini, mylohyoid and ant bellie of digastric.
Trigeminal sensory
Discriminative touch, vibration sense and proprioception of mobile head structures
Protopathic, pain and heat sense from spinal nucleus
CN 5 spinal nucleus
Carries GVA extends from mid pontine to CN 5 entry at C2,3. Concerned with pain and temperature
Spinal nucleus Innervation
Receives Innervation from 5,7, 9 and 10
Incoming neurons descend down the spinal trigeminal tract to terminate in the spinal nucleus
Pars oralis- concerned with protopathic touch.
Pars interpolaris- touch, spine pain and temporature (teeth)
Pars caudlis- primarily pain and temperature.
Primary sensory nucleus of V
Receives large diameter fibers for discriminative touch and pressure , equivalent to th dorsal column nuclei for the face.
GSA
Mesencephalic nucleus GSA
Extends upward toward the caudal midbrain, primary sensory neurons homologous to dorsal nucleus of Clarke, functionsin proprioception for muscle of mast. And refle control of bite.
Has extensive projections to the motor nucleus of V.
Ascending tracts from sensory nuclei
Ventral and dorsal trigeminothalamic
V- crossed sends fibers to thalamus
D- uncrossed sends fibers to the thalamus
CN 6
Upper pons
Blood supply to the upper pons
is primarily from branches of the basilar a. But includes also the sup. cerebellum a.
Branches of basilar a.
Para median a.- median pontine tegmentum
Short circumfrential- lat. pont. Tegmentum
Long circ- upper and dorsolateral pons.
Superior cerebellar a.
Supplies upper dorsolateral pons.
