CV V Trigeminal Nerve

Question 1

What is xerostomia?

Answer 1

dry mouth

Question 2

what is dysgeusia?

Answer 2

altered ability to taste

Question 3

what does palsy mean?

Answer 3

paralysis

Question 4

what is strabismus?

Answer 4

misalignment of one or both globes

Question 5

where is the nucleus of the trigeminal nerve?

Answer 5

within the brain stem (very long and big nucleus so starts mid pons and extends down to the upper spine)

Question 6

what are the intracranial exit of CN V?

Answer 6

Superior orbital fissure
foramen rotundum
foramen ovale

Question 7

what is the extracranial exit of CN V?

Answer 7

distal to the foramina

Question 8

which divisions of CN V have sensory function? which has motor?

Answer 8

All 3 sensory
only V3 motor

Question 9

what are the motor innervations of CN V3?

Answer 9

Muscles of mastication
Tensor Veli palatini
Tensor tympani
anterior belly of digastric
mylohyoid

Question 10

what are the sensory innervations of CN V2?

Answer 10

–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

Question 11

what is the sensory innervations of CN V3?

Answer 11

–facial skin of lower 1/3 of face, chin, lower lip
–mandibular teeth and gingiva
-anterior 2/3 tongue (pain/temp)

Question 12

what nerve gives taste for the anterior 2/3 of tongue?

Answer 12

chorda tympani from CN VII

Question 13

where are the motor UMN of the trigeminal nerve?

Answer 13

primary motor cortex

Question 14

where is the motor LMN nucleus of CN V?

Answer 14

Pons (just above CN VII nucleus)

Question 15

what is the path taken of CN V?

Answer 15

UMN project to corona radiata (white matter band)
internal capsule
crus cerebri
CN V nucleus (terminates BILATERALLY here)

Question 16

How does UMN of CN V terminate?

Answer 16

bilaterally at the LMN

Question 17

what is important about the termination of CN V?

Answer 17

makes it harder to detect lesions coming from one side the UMN because the other side will condensate

Question 18

where will a lesion become noticeable?

Answer 18

from the location of the LMN and on will produce IPSILATERAL loss of muscle function

Question 19

where are the first, second and third order neurons of CN V?

Answer 19

1- trigeminal ganglion
2-princical, spinal or mesencephalic nucleus
3- VPM nucleus in thalamus, terminates in the somatosensory cortex

Question 20

Where does proprioception information go?

Answer 20

mesencephalic nucleus (tells us where tongue and teeth are, calculating bite force for different foods etc)

Question 21

where does tough, pressure and vibration sensations go for CN V?

Answer 21

main sensory nucleus

Question 22

where does pain and temperature information go for CN V?

Answer 22

spinal nucleus

Question 23

VPM neurons project to the primary somatosensory cortex via ___________

Answer 23

posterior limb of the internal capsule

Question 24

what part of the somatosensory cortex perceives the face?

Answer 24

the most lateral part

Question 25

where are the CN V parasympathetic neurons?

Answer 25

no where, they do not exist
BUT parasympathetics hitch a ride on trigeminal nerves to get the their destination (all 4 parasympathetic ganglia)

Question 26

where are the preganglionic parasympathetic fibers for the intraocular muscles of the globe?

Answer 26

within CN III (synapse in ciliary ganglion)

Question 27

Where is the postganglionic parasympathetics?

Answer 27

hitchhike on short ciliary nerve (V1)

Question 28

where are preganglionic fibers for the lacrimal, submandibular and sublingual glands?

Answer 28

within CN VII

Question 29

where does the CN VII parasympathetics synapse for the lacrimal glands?

Answer 29

pterygopalatine ganglion

Question 30

where are the postganglionic fibers for the lacrimal glands?

Answer 30

hitchhiking on CN V2, and V1 branches to lacrimal glands

Question 31

where does the CN VII parasympathetics synapse for the submandibular and sublingual glands?

Answer 31

submandibular glands

Question 32

where are the postganglionic fibers for the submandibular and sublingual glands?

Answer 32

hitchhike on V3 lingual nerve

Question 33

where are the preganglionic fibers for the parotid glands?

Answer 33

within CN IX

Question 34

where does the parasympathetic preganglionic nerves synapse?

Answer 34

otic ganglion

Question 35

where do the postganglionic fibers travel for the parotid gland?

Answer 35

auriculotemporal nerve (branch of V3)

Question 36

what does the jaw jerk test test for?

Answer 36

afferent and efferent limb of CN V
(issue with CN V can cause lack of reflex or clonus)

Question 37

what is the the blink reflex, what does it test for?

Answer 37

poke one eye, both should close
afferent: CN V1
efferent: CN VII (direct and consensual response)

Question 38

where do CN V1, V2 and VI come close?

Answer 38

cavernous sinus