Cuts of Pons/ Midbrain Flashcards
What are the cuts of the Pons
5- Cut thru caudal pons
6- Cut thru cranial pons
What are the cuts of the Midbrain
7- Cut thru caudal midbrain
8- Cut thru Cranial midbrain
notable contents of cut 5 (caudal pons) (5)
Bundles of corticospinal neurons and corticonuclear bundles (from primatry somatomotor cotex)
Pontine nucleus- Send info about intention of mvmt to CL cerebellum (thru middle cerebellar peduncle)
Facial colliculus- has motor nucleus of amducens and motor nuc of facial
Medial lemnicus
trapezoid body- Crossing chochlear fibes that go to lat lemnicus
Notable contents of cut 6 (cranial pons) (4)
Motor nuc of trigeminal (to massicatory mm)
Sensory nuc of trigeminal
Sup cerebellar peduncle (midbrain to cerebellum)
Medial eminence- created by medial longitudinal fasciculus (from med vestibular nucleus to CN 3,4,6z)
What identifys cut 7 from 8
Big decussating fibres of superior cerebellar peduccle
and red nucleus in cut 8
Notable contents of caudal midbrain (cut 7)
decussasion of sup cerebellar peduncles
trochlear n
cerebral peduncles
Substantia niagra
periaquaductal grey matter
inf colliculus
cochlear fibres
mesencephalic nut of trigeminal
What is the decussation of sup cerebellar peduncles (cut 7(
efferent conection of cerebellum thru superior cerebellar peduncles
when in midbrain they cross midline and go to red nucleus where it is either sent to thalmus or cross back to ant tegmental decussation
what is the periaquaductal grey matter (cut 7)
Sorunds cerebral aquaduct and control some pain modulation thu endogenous opiods
What oocupies the each middle path of the cerebral peduncles
corticospinal tract
Corticobulbar tract- path that goes to CN 5,7,12 and ambigous nuc)
Corticopontine
What travels thru lat lemnicus + efffernt (cut 7)
Lat lemniscus is 50% fibres from CL chochlear n and 50% from IL chochlear n
can be sent to Medial geniculate body or Inf colliculus (where it goes to medial geniculate body or CL side thry tecto spinal tract)
What is the mesencephalic nuclus of trigeminal n for (cut 7)
For proprioception from head
Notable structures of cranial Midbrain (cut 8)
red nucleus- sends info to CL rubrospinal tract and IL inf olivary complex From cerebellum
Nucleus of occulomotor n
Sup colliculus (visual reflex pathway)
medial lemniscus
Spinal lemniscus (spinothalamic axons to thalmus)
Trigeminal lemnicus
medial longitudinal fasiculus- for fixation of target w eyes)