CV V Trigeminal Nerve Flashcards
What is xerostomia?
dry mouth
what is dysgeusia?
altered ability to taste
what does palsy mean?
paralysis
what is strabismus?
misalignment of one or both globes
where is the nucleus of the trigeminal nerve?
within the brain stem (very long and big nucleus so starts mid pons and extends down to the upper spine)
what are the intracranial exit of CN V?
Superior orbital fissure
foramen rotundum
foramen ovale
what is the extracranial exit of CN V?
distal to the foramina
which divisions of CN V have sensory function? which has motor?
All 3 sensory
only V3 motor
what are the motor innervations of CN V3?
Muscles of mastication
Tensor Veli palatini
Tensor tympani
anterior belly of digastric
mylohyoid
what are the sensory innervations of CN V2?
–lower eyelid and its conjunctiva
–inferior posterior portion of the nasal cavity
–all cheeks and maxillary sinus
–lateral nose
–upper lip, max teeth and gingiva
–superior palate
what is the sensory innervations of CN V3?
–facial skin of lower 1/3 of face, chin, lower lip
–mandibular teeth and gingiva
-anterior 2/3 tongue (pain/temp)
what nerve gives taste for the anterior 2/3 of tongue?
chorda tympani from CN VII
where are the motor UMN of the trigeminal nerve?
primary motor cortex
where is the motor LMN nucleus of CN V?
Pons (just above CN VII nucleus)
what is the path taken of CN V?
UMN project to corona radiata (white matter band)
internal capsule
crus cerebri
CN V nucleus (terminates BILATERALLY here)
How does UMN of CN V terminate?
bilaterally at the LMN
what is important about the termination of CN V?
makes it harder to detect lesions coming from one side the UMN because the other side will condensate
where will a lesion become noticeable?
from the location of the LMN and on will produce IPSILATERAL loss of muscle function
where are the first, second and third order neurons of CN V?
1- trigeminal ganglion
2-princical, spinal or mesencephalic nucleus
3- VPM nucleus in thalamus, terminates in the somatosensory cortex
Where does proprioception information go?
mesencephalic nucleus (tells us where tongue and teeth are, calculating bite force for different foods etc)
where does tough, pressure and vibration sensations go for CN V?
main sensory nucleus
where does pain and temperature information go for CN V?
spinal nucleus
VPM neurons project to the primary somatosensory cortex via ___________
posterior limb of the internal capsule
what part of the somatosensory cortex perceives the face?
the most lateral part
where are the CN V parasympathetic neurons?
no where, they do not exist
BUT parasympathetics hitch a ride on trigeminal nerves to get the their destination (all 4 parasympathetic ganglia)
where are the preganglionic parasympathetic fibers for the intraocular muscles of the globe?
within CN III (synapse in ciliary ganglion)
Where is the postganglionic parasympathetics?
hitchhike on short ciliary nerve (V1)
where are preganglionic fibers for the lacrimal, submandibular and sublingual glands?
within CN VII
where does the CN VII parasympathetics synapse for the lacrimal glands?
pterygopalatine ganglion
where are the postganglionic fibers for the lacrimal glands?
hitchhiking on CN V2, and V1 branches to lacrimal glands
where does the CN VII parasympathetics synapse for the submandibular and sublingual glands?
submandibular glands
where are the postganglionic fibers for the submandibular and sublingual glands?
hitchhike on V3 lingual nerve
where are the preganglionic fibers for the parotid glands?
within CN IX
where does the parasympathetic preganglionic nerves synapse?
otic ganglion
where do the postganglionic fibers travel for the parotid gland?
auriculotemporal nerve (branch of V3)
what does the jaw jerk test test for?
afferent and efferent limb of CN V
(issue with CN V can cause lack of reflex or clonus)
what is the the blink reflex, what does it test for?
poke one eye, both should close
afferent: CN V1
efferent: CN VII (direct and consensual response)
where do CN V1, V2 and VI come close?
cavernous sinus
