Pons Flashcards
Glossopharyngeal sensory
Primary in the inferior ganglion
SVA - posterior 1/3 of tongue taste terminates in solitary nucleus
GSA - posterior 1/3 of tonuge, pharynx, middle ear terminates in spinal trigeminal nucleus
GVA - carotid body and sinus terminate in caudal 2/3 of solitary nucleus
Snesory portion of gag reflex
Motor of glossopharyngeal
SVE - stylopharyngeus…LMN in nucleus ambiguus
GVE - parotid gland…preganglionic para in the inferior salivary nucleus
Vestibulocochlear vestibular portion
SSA
Primary in vestibular ganglion and terminate in vestibular nuclei
Vestbiulocochlear auditory portion
SSA
Primary in spiral ganglion and terminate in cohclear nuclei
Unilateral deaf means
Lesion more superficial than the cochlear nucleus…after cochlear nucleus, will go bilaterally
Stage 1 acoustinc neuroma
affects CN 8 - ipsi loss of hearing and balance
Stage 2 acoustic neuroma
CN 8 - ipsi loss of hearing and balance
Inf cerebellar peduncle - ipsi ataxia
Spinal trgemin - ipsi loss of pain and temp from face
Root of 9 - loss of gag reflex and difficulty swallowing
Root of 7 - ipsi facial paralysis
Middle cerebellar penducle contains
Pontocerebellar fibers from contralateral pontine nuclei
Cerebellar circuit involving pontine nuclei
Corticospinal start at cerebral cortex and have branch that comes off at ipsi pontine nuclei…pass to contra superior cerebellar penducle…goes to contra VPL of the thalamus and back to the cerebral cortex.
Therefore lesion to superior cerebellar peduncle leads to ipsi ataxia
Facial nerve motor
SVE - in facial motor nucleus…fibers loop around abduens nucleus
Sensory facial nerve
primary in geniculate ganglion
SVA - taste (ant 2/3)terminate in nucleus solitarius
GSA - outer ear terminate in trigeminal nuclei
UMN and LMN damage to facial motor nucleus
UMN above the pons will only paralyze the lower half of the face contra to the lesion
LMN below the pons will paralyze entire face ipsi to the lesion
Bell’s palsy
From Unilateral LMN lesion…forehead not okay and downturned mouth
UMN lesion of facial nerve
Forehead okay but downturrned mouth
Abducens neuron locations
LMN innervate lateral rectus
UMN located in frontal eye fields of cortex
RF and abducens
PPRF just anterior and imoportant for conjugate gaze
Lesion abducens nerve and nucleus
Nerve - diplopia
Nucleus - lateral gaze paralysis…neither eye can look to lesioned side
LSO and MSO
Locating high frequency objects in space
LSO - high frequency
MSO - low frequency
Principal trgeminal nucleus
Pass through middle cerebellar peduncle and carry 2 point touch, proprio and vib from the face
Neurons project bilaterally to the VPM in the DTT
Motor trgeminal nucles
LMN innervating mastication asnd tensor tympani
Spinotrgeminal nucleus
Neurons project to VPM in the VTT
Lesion spinal trgemin nucleus or principal nucleus
Spinotrigem - ipsi loss of pain and temp
Principal nucleus - ipsi loss of 2 point, vib, or proprioception
Lesion of VTT or DTT
VTT - contralateral loss
DTT- may not be able to tell
Muscles of motor trigeminal nucleus
Masseter, medial and lateral pterygoid and temporalis
Tensor tympani
If LMN lesion of motor trigeminal fibers
paralysis of ipsilateral muscles of mastication and hyperacusis to sound
Corneal reflex
When you touch eye, goes to ipsi principal nucleus and spinal trigeminal nucleus..
If painful, spinal trigeminal has interneurons that synapse with facial motor nuclei and cause blinking of both eyes
Lesion affarent portion of trigeminal nerve or efferent/ipsi facial nucleus portion of nerve in corneal reflex
Affarent - neither eye blinks if ipsi touched…both eyes blink if contra touched
Efferent - If touch ipsi, then only contra blinks…if touch contra, then only contra blinks
Mesencepahlic nucleus
Located in periaqueductal gray area and controls force of bite…neural crest cell derived
Locus ceruleus
Noradrenergic neurons extensive rostral and caudal through CNS…involved in arousal, sensory modulatio nand motor tone
Dysarthria syndrome
Medial pontine syndrome
Paramedian branches of basilar artery
Corticospinal tract - contra UMN signs
Medial lemnisucs - contral loss of vib, proprio, and fine touch
VTT - contra loss of pain and temp form face
Facial nerve roots - ipsi facial muscle weakness
Abducens root - ipsi paralysis of LR
Lateral pontine syndrome
Mid cerebellar peduncle - ipsi ataxia
Spinal trigeminal tract - ipsi loss of pain/temp from face
Anterolateral tract - contra loss of pain and temp from body
Hypothal descencing fibers - ipsi Horner’s syndrome
