S6: Internal and External Anatomy of the Pons Flashcards

Middle Cerebellar Peduncles

CN 5

CN 6

CN 7

Superior Cerebellar Peduncles

basis of the pons
16

facial colliculus


vestibular area

pontine tegmentum

Abduscens nuclei
supplied by: perforating branches of basilar


Facial Nerve
supplied by anterior inferior cerebral a.


medial lemniscus
supplied by mostly branches from the basilar


lateral lemniscus


Superior olive
supplied by AICA ?


Vestibular nulcei
supplied by AICA


Medial longitudinal fascilus
supplied by perforating basilar a.


Paramedian Pontine Reticular formation


Rubrospinal tract


ALS
supplied by AICA


Spinal n. of trigem.
supplied by AICA


Spinal tract of trigem.
supplied by aica


inferior cerebellar peduncle


superior cerebellar peduncle


corticospinal tract
supplied by perforating branches of basilar


middle cerebellar peduncle


medial lemniscus


rubrospinal tract


ALS


Motor nucleus of trigem
supplied by AICA
function: somatosensory for head and neck and motor jaw muscles
pathology: numbness in head and neck on SAME SIDE
weakened chewing
sensory loss elsiminating corneal reflexing -> irritated cornea


principal sensory of trigem.
function: epicritic from head and neck
pathology: reduced 2 point tactile, fibration, position sense on SAME SIDE of head


CN 5: Trigem
function: somatosensory for head and neck, motor for jaw
pathology: numbness in head and neck on the same side, weakened chewing, sensory loss eliminates corneal reflex resulting in irritated cornea


lateral lemniscus
function: hearing
pathology: no obvious pathology (from unilateral X)


Superior olive
function: hearing, particularly in locating the source of sound
pathology:
unilateral - nothing, due to bilaterality of auditory pathway


Decussation of the trapezoid body
function: 1. somatosensory for trunk and limbs (medial lemniscus)
2. autditory: crossing lateral lemniscus fibers
pathology:
- loss of epicritic sense for trunk and limbs
- no obvious hearing loss


Locus Ceruleus
function: main source of Norepeinphrine, motor control and sleep; adjusts muscle tone during rem
Pathology: prevents collapse of tone during REM (in cats…), implicated in parinksonism


Medial longitduinal fasiculus
function: coordinates head and eye position
pathology: itnernuclear opthalmoplegia; contralateral eye cannot adduct for conjugate gaze shift but can adduct during convergence


pontine nuclei

Medial longitudinal fasciculus
function: coordinates head and eye position
pathology: contralateral eye cannot adduct for conjugate gaze shift, can adduct during convergence


locus ceruleus
function: main source of norepeinhrpine; motor control and sleep; adjusts muscle tone during REM
pathology: implicated in parinksoniasm, prevents collapse of tone during REM sleep


superior cerebellar peduncle
pathology: cerebellar signs: ataxia, intention tremor
connections: o carries most of cerebellums output to other parts of the brain
• main ouput:
areas of pontine reticular formation
red nucleus in the midbrain
ventral anterior and ventral alteral nucleus in the thalamus -> precentral gyrus and premotor cortex


medial lemniscus
function: epicritic somatosensory for trunks and limbs on OPPOSITE SIDE
pathology: loss of 2 point, vibration, position sense, asterogonosis, shuffling gait etc.


crus cerebri
function:
cortical control of movement and some descending gating of sensory signals
pathology: 1. loss of indepdent finger movement
2. slowed rxn times
3. slight weakness


lateral lemniscus
function: hearing
pathology: no obvious sx from unilateral X


Corticospinal tract
function: motor contorl from cortex to motor neurons of CN and ventral horn
isolated pathology: loss of indepdent finger control, slowed rxn times


facial nculeus


superior cerebellar peduncle

dentate nucleus

inferior cerebellar peduncle

middle cerebellar peduncle