section 6: part 2 Flashcards
what is the locus ceruleus important for?
for vigilance & responsiveness to unexpected stimuli
what is the “trapezoid body”
it is a region containing the crossing auditory axons and the medial lemnisucs
where do the auditory axons terminate?
superior olive
also in the nucleus of trapezoid body, nucleus of lateral lemiscus
what do the auditory axons go on to form?
the lateral lemniscus
where does the lateral lemnicus terminate?
the inferior colliculus of the midbrain
what nuclei controls the muscles of the jaw?
the motor nucleus of 5
what does the principal/chief nucleus of 5 do?
processes epicritic sensory information from the face
what nuclei receives pain & temp info from the face?
spinal nucleus of 5 in the medulla
what nucleus carries proprioceptive info involved in jaw reflexes to the motor nucleus of 5?
the mesencephalic nucleus of 5
what does the medial lemniscus carry?
somatosensory info
what structures does the medial longitudinal fasciculus interconnect?
innerconnects the superior colliculus, vestibular nuclei, cranial nerve nuclei-3,4,6 and the cervical spinal cord
what type of info does the MLF carry?
info coordinating head & eye movements
what are the symptoms of destruction to the MLF?
horizontal nystagmus
loss of conjugate horizontal eye movements
what two muscles are necessary for horizontal eye gaze? who controls their movements?
lateral rectus of 1 eye and the medial rectus of the over
(nerves 6 and 3) coordinated by the MLF tract
is a person still able to do vergence of the two eyes with a pathology in the MLG
yes
what structure is referred to as the “horizontal gaze center”?
the paramedian pontine reticular formation (PPRF)
what does the PPRF do?
coordinates the horizontal eye movements
what is the function of the vestibular nuclei?
receives sensory info about head movements and position from the 8th nerve
what are the 3 prominent outputs of the vestibular nuclei?
- to the cranial nerve nuclei to move eyes via the MLF
- to the spinal cord via vestibulospinal tracts imp for posture
- to the cerebellum via the inferior cerebellar puduncle -role in balance & control of reflexive eye movements
what are some symptoms of a vestibular nuclei pathology?
nystagmus
loss of balance
vertigo, dizziness, nauseousness
what is a positive romberg sign and when is it seen?
loss of balance when the eyes are closed
seen in a vestibular nuclei pathology
what muscles does the motor nucleus of 5 innervate?
facial muscles, stapedius, auricularis, stylohyoid muscles & posterior belly of digastric
what is the result of a pathology to the facial nucleus?
- paralysis of ipsilateral facial muscles
- mouth droops
- patient unable to close eyes
- loss of parasymp control of lacrimal gland
- loss of corneal reflex
- painful sensitivity to sound (due to loss of strapeidus innervation)
what is the function of the abducen’s nuclei?
innervates the lateral rectus muscle of the IPSILATERAL eye
what is the symptom of a pathology in the abducen’s nuclei?
paralysis of ipsilateral lateral rectus muscle
eye deviates towards nose (internal strabismus) leading to double vision
what does the caudal end of the spinal nucleus of 5 do?
pain & temp info from the face
what does the rostral end of the spinal nucleus of 5 do?
epicritic info from the face
what is the principal/chief sensory nucleus of 5 do?
epicritic sensation for head & neck
info from SAME side
where does epicritic info from the face terminate?
ventral posteriomedial nucleus (VPM) of the thalamus
what is the function of the motor nucleus of 5?
innervates muscles of mastication on the SAME side of face
what are the symptoms of a pathology of the motor nucleus of 5?
paralysis of the ipsilateral muscles of mastication
weakness in chewing
jaw juts sideways when protruded
