Clinically Relevant Anatomy of Cranial Nerve Testing Flashcards Preview

RB Y3 1.1 Neuroanatomy > Clinically Relevant Anatomy of Cranial Nerve Testing > Flashcards

Flashcards in Clinically Relevant Anatomy of Cranial Nerve Testing Deck (24)
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1
Q

outline CNI course

A
  • extracranial part in olfactory mucosa in nasal cavity
  • 1st neuron: receptor cells pass through cribriform plate of ethmoid bone. these are replaced every so often by the basal cells
  • 2nd neuron: olfactory bulb
  • the olfactory tract ends in temporal lobe
2
Q

what is different about CNI

A

it is the only sensory modality that doesnt synapse at the thalamus prior to reaching the cortex

the neurons are in contact with the outside world

3
Q

outline CNII course

A
  • formed from ganglion at back of retina
  • passes through optic canal in sphenoid bone in middle cranial fossa
  • travels to optic chiasm to form optic tract
  • connects to CNS at diencephalon
  • LGN in the thalamus is a connection point for it then to go to the primary visual cortex in the occipital lobe (level 4C)
4
Q

how do you test CNI

A

not routinely done, cover one nostril and ask the patient to smell a familiar smell

5
Q

outline CNIII course

A
  • connects with CNS in midbrain
  • travels towards orbit in lateral wall of cavernous sinus
  • goes through superior orbital fissure
  • supplies extraocular muscles and parasympathetics synapse in ciliary ganglion
6
Q

outline CNIV course

A
  • comes off posterior aspect of midbrain
  • travels towards orbit in lateral wall of cavernous sinus
  • goes through superior orbital fissure
  • supplies superior oblique muscle ONLY
7
Q

why is CNIV susceptible to damage

A

very long and thin

8
Q

outline CNVI course

A
  • comes off pontomedullary junction
  • travels towards orbit in the cavernous sinus (not on lateral wall)
  • goes through SOF
  • supplies only lateral rectus muscle
9
Q

outline CNXI course

A
  • connects with CNS at cervical spinal cord
  • ascends through foramen magnum and travels towards jugular foramen in posterior cranial fossa
  • exits via jugular foramen in posterior cranial fossa
  • supplies SCM and trazpezius
10
Q

outline how to clinically test CNXI

A
  • shrug shoulders and turn head against resistance
11
Q

outline CNXII course

A
  • connects with CNS via rootlets lateral to the pyramids of the medulla
  • passes through hypoglossal canal in posterior cranial fossa
  • descends lateral to carotid sheath (contains common and internal carotid artery and IJV and CNX)
  • at the level of the hyoid bone turns anteriorly towareds the lateral aspect of the tongue
  • supplies muscles in tongue (except palatoglossus)
12
Q

CNXII clinical testing

A

ask patient to stick tongue out, tongue tip points towards side of injured nerve

13
Q
A
14
Q

which muscle of mastication opens the jaw

A

lateral pterygoid

15
Q

which muscle in the palate and ear does CNV3 supply

A

tensor veli palatini and tensor tympani

16
Q

attachments of masseter

A
  • angle of mandible
  • zygomatic arch/bone
17
Q

attachment of temporalis

A

coronoid process of mandible

18
Q

outline CNVII course

A
  • CNS connection at pontomedullary junction
  • goes into internal acoustic meatus in posterior cranial fossa to enter middle ear cavity in petrous part of temporal bone
  • leaves via stylomastoid foramen
  • geniculate ganglion here is an L shaped collection of sensory neurons of this nerve
  • somatic motor axons pass into parotid gland then supply muscles of facial expression
  • also special sensory (taste) and parasympathetic (submitted by chorda tympani??)
19
Q

stapedius muscle

A
  • CNVII in middle ear cavity in petrous temporal bone
  • reduces stapes movement to protect the internal ear from excessive noise
20
Q

chorda tympani course

A
  • piggy backs on the lingual nerve (CNV3) transmitting taste to the anterior 2/3rd of tongue and parasympathetic fibres to the submandibular and sublingual glands
21
Q

name 4 movements to clinically test motor function of CNVII

A
  • raise eyebrows
  • close eyes tightly
  • smile
  • puff out cheeks and hold air
22
Q

CNIX supplies

A
  • somatic motor: stylopharyngeus muscle
  • special sensory: vallate papillae (have taste buds) on posterior 1/3 of tongue
  • parasympathetic: parotid gland
  • general sensory: pharyngeal mucosa (laryngopharynx also CNX), posterior 1/3 of tongue, palatine tonsil, eustahcian tube, middle ear cavity
  • visceral afferents: carotid body and sinus
23
Q

how to test CNIX

A

elicit gag reflex

24
Q

clinical testing of CNX

A

open mouth and say ahhh - uvula will be pulled away from non functioning side