Neuro L4 Flashcards
Divisions of CNV
Name
motor or sensory
TRIGEMINAL NERVE
Opthalmic: sensory
Maxillary: sensory
Mandibular: sensory and motor
Trigeminal motor nucleus located in
Dorsal pons
Mesencephalic nucleus
Fiber myelination
Homologue of
Function
Heavily myelinated
Posterolateral column: Medial lemniscus system
Proprioception
Main/principal sensory nucleus
Fiber myelination
homologue of
Function
Heavily myelinated
Posterolateral column: Medial lemniscus system
Discriminative touch/vibration
Spinal nucleus
Fiber myelination
Homologue of
Function
Lightly myelinated fibers
Homologue of anterolateral system
Pain, crude touch, temperature
Trigeminal main/principal sensory nucleus location
midpons
CN V Sensory afferent serves (3)
Face
Oral cavity
Meninges
V main sensory nucleus ascending crossed pathway joins
Joins medial lemniscus
V main sensory nucleus ascending uncrossed comes from _____ and goes to _____
Comes from mouth and goes to Ventral Posteromedial nucleus
Spinal trigeminal afferents ascend/descend spinal trigeminal tract and synapse in_____
descend
synapse in caudal spinal nucleus
Second order spinal trigeminal afferents pathway
cross midline
Ascend and join spinothalamic tract
Second order spinal trigeminal afferents terminate in
VPM
Trigeminal mesencephalic nucleus located in
midbrain
Onion peel
Pars caudalis
Pars caudalis
Primarily what type of fibers
pain fibers
Pars Caudalis organization
Onion peel
Rostral: oral
Caudal: peripheral face
Pars caudalis receives afferents from these cranial nerves
VII
IX
X
Substantia gelatinosa of pars Caudalis
contains these neurons
excitatory and inhibitory interneurons
Substantia gelatinosa of pars Caudalis
Receives
Raphe spinal tract fibers (serotonin)
Pars Caudalis somatotopic arrangements Mandibular Opthalmic Maxillary Fibers representing center of face Fibers representing back of face
Mandibular: dorsal Maxillary: in between Opthalmic Ventral end near obex upper cervical cord
The more rostral/caudal the spinal trigeminal tract injury, the larger the area around the mouth that is spared of sensory loss
Caudal
Trigeminal spinal nucleus has _____ projection to _______
contralateral projection to VPM of thalamus (internal capsule…postcentral gyrus parietal lobe (Brodmanns area 312))
Trigeminal main sensory nucleus has _____ projection to _______
bilateral projection to VPM of thalamus (internal capsule…postcentral gyrus parietal lobe (Brodmanns area 312))
Trigeminal neuralgia
Usually in
Usually caused by
Brief episodes of excruciating pain in division of trigeminal nerve
Mandibular (70%)
Opthalmic (
Treating trigeminal neuralgia (incorrect)
cut nerve root results in lossa of pain AND all tactile sensation, temp, and proprioception
Danger of Treating trigeminal neuralgia while saving tactile sensation
Cut occurs caudal to obex near medulla
Compromises medullary cardiovascular and respiratory centers
modern way of treating trigeminal neuralgia
microvascular decompression
Trigeminal mesencephalic nucleus terminating in trigeminal motor nucleus is involved in
jaw jerk reflex
Trigeminal mesencephalic nucleus terminating in supratrigeminal nucleus is involved in
chewing movements
Trigeminal mesencephalic nucleus sense
proprioception
Trigeminal mesencephalic nucleus proprioception receptors
Nueromuscular spindles of mastication muscles
Pressure/tension receptors in perio ligaments
Mesencephalic nucleus type of cell body
unipolar
Mesencephalic nucleus projects to (2)
Trigeminal motor nucleus
Supratrigeminal nucleus
Mesencephalic nucleus helps control
distance between mandible and maxilla
Trigeminal motor nucleus terminates in
muscles of mastication
Lesion to trigeminal motor nucleus causes
weaked jaw closure
opened jaw will deviate toward side of lesion
Supratrigeminal nucleus function
pattern generator for masticatory rhythm
Trigeminal motor nucleus innervates (3)
MOM
Tensor tympani
Tensor palati
Jaw jerk reflex
How many synapses
Afferent limb (innervating what muscle)
Efferent limb
monosynaptic
Afferent: mesencephalic V innervating masseter spindle
Efferent: V motor nucleus
Major connections of trigeminal nerve (4)
masseter muscle spindles (mechanoreceptor)
Tactile afferents
Muscles of mastication (motor)
Pain/temperature afferents
Actions of CNVII
Motor: Facial expression Stapedius muscle (modulates sound) Sensory: Skin of outer ear Palatine tonsil and posterior nasal cavity Taste Salvation Lacrimation
Somatic sensory component of CNVII act exactly as
trigeminal afferents
Facial motor innervation of upper and lower face
Laterality
Upper: bilaterally
Lower: contralateral
Damage to cerebral peduncle
What pathway
Consequences
Damage to corticobulbar pathway
inability to smile symmetrically but forehead unaffected
Bell’s Palsy
symptoms
VII dysfunction
Paresis of facial muscles above and below eye
Hyperacusus (stapedius)
Reduced lacrimation and salvation
Corneal blink reflex
Afferent limb
Efferent limb
V1 to spinal V nucleus
Spinal V nucleus/reticular formation bilateral projection to VII
CN dealing with taste
VII
IX
X
Nervus intermedius lies between and aligns with _____ distal to ______
lies between VII and VIII
Aligns with VII distal to genu
Taste input go to
rostral aspect of solitary tract nucleus
VII pathway from tongue
Look at picture
Second order gustatory afferents travel to the ______ thru the ______
solitary tract nucleus thru the solitary tract
Gustatory fiber pathway
Project uncrossed to thalamus (VPM) then to gustatory cortex
integrates witholfactory info
amygdala
limbic system and hypothalamus
In pontine tegmentum: most fibers go to this nucleus
supratrigeminal
Mesenchephalic nucleus gets info from this in Mandibular division
MOM stretch receptors (spindles) Stretch receptors (ruffini endings) in suspensory and perio ligaments
Mesencephalic nucleus gets into from this in Maxillary division
Stretch receptors (ruffini endings) in suspensory and perio ligaments
