Cranial Nerves Review

Question 1

CN1 path

Answer 1

axons pass thru cribriform plate of the ethmoid bone
-symapse in mitral cells and pass backwards in the olfactory tract
-end in the primary olfactory cortex whichh is located in the temporal blob

Question 2

what is the only cranial nerve that does link to thalamus

Answer 2

CN1

Question 3

What is the path of CNII

Answer 3

Visual impulses sent via the optic nerve which meet at the optic chasm

fibres from the optic tract synapse in the lateral geniculate body of the thalamus and continue as optic radiation to primary visual cortex

Question 4

what happens if there is damage at optic chasm, optic radiation and primary visual cortex

Answer 4

optic chasm- bitemporal hemianopia

Optic radiation- homonymous hemianopia

Visual cortex- Homonymous hemianopia w macular sparing

Question 5

what parasympathetic fibres does CNIII carry

Answer 5

to the iris mm via the colliery ganglion from the Edinger-Westphal nucleus (in midbrain)

For constriction of the pupil and lens occomidation

Question 6

What does CNIV do

Answer 6

sup oblique mm

-turns the eye down and out

Question 7

What is the only cranial nerve that exits brainstem dorsally

Answer 7

CNIV

Question 8

where is the motor nucleus of CNV seen and what does it supply `

Answer 8

Pons
-supplies the mm of mastication

Question 9

where are the three parts of the sensory trigeminal nucleus located and what do they carry

Answer 9

Mesencephalic (carries proprioception)- located in midbrain

Main sensory (carrying touch)- in pons

Spinal (carriying pain + temp) in medulla and extends into the upper cerv segments

Question 10

What is the pterygopalatine ganglion attached to and what does it inn

Answer 10

attached to maxillary div of CNV

-recieves parasympathetic fibres from sup salivary nucleus of CN7

Question 11

what does the otic ganglion attach to and what does it inn

Answer 11

attached to auriculotemporal branch of the mandibular div of CNV

recieves parasympathetic fibres from inf salivary nucleus of CNIX

Question 12

What is the submandibular ganglion attached to and what does it inn

Answer 12

Attached to lingual branch of the ant div of mandibular div

-recieves parasympathetic fibres from sup salivary nucleus via CNVII

Question 13

what are the 4 nuclei of the facial nerve

Answer 13

motor (motor nucleus in pons)
Ordinary sensation (sensory nucleus of the trigeminal n)
Parasympathetic (sup salivary nucleus)
Taste (solitary tract nucleus)

Question 14

What are the 5 branches of the facial nerve mm

Answer 14

Ten Zebras Broke My Car
-Temporal
-Zygomatic
-Buccal
-marginal mandibular
-cervical

Question 15

what other mm does the facial nerve innervate other than facial mm

Answer 15

stylohyoid

post belly of digastric

Question 16

where does the facial nerve conduct taste from

Answer 16

ant two thirds of the tongue via the nucleus solitarius

Question 17

where does the facial nerve carry parasympathetic fibres

Answer 17

from sup salivary nucleus to the submandibular and sublingual salivary glands via sub,amdibular ganglion of CV V3

Question 18

what does the facial nerve carry general sensory afferents from

Answer 18

skin of the external ear canal via the auricular branch of CNX

Question 19

CN8 cochlear nerve fibres pathway

Answer 19

transverse the int auditory meatus to reach lat aspect of the medualla

terminate in dorsal and ventral cochlear nuclei in midbrain

cross over to opposite side ending in nuclei in trapezoid body

assent thru inf colluculos to medial geniculate body in thalamus to pro,aary auditory cortex

Question 20

vestibular fibres of CN8 pathway

Answer 20

semicircular canals
-enter medulla and end in the vestibular nuclei located in the floor of the 4th ventricle

-many efferent fibres from vestibular nuclei pass to the cerebellum thru inf peduncle

Question 21

what motor fibres does CN9 carry

Answer 21

motor fibres from nucleus ambiguous to stylipharyngeus mm

Question 22

What sensory fibres does CN9 have

Answer 22

sensation from post 1/3 of tongue and phaeynx to sensory nucleus of CNV

parasympathetic inn to parotid gland via the otic ganglion of CNv3 from inf salivary nucleus in the medulla

Also supplies carotid body (chemoreceptors) and carotid sinus (baroreceptors)

Question 23

what are the 5 afferent/efferent paths of the vagus nerve

Answer 23

1. General somatic efferent- Nucleus ambiguous (skeletal m)
2. General Visceral efferent- dorsal motor nucleus of CNX (visceromotor)

3, General somatic afferent- spinal nucleus of CNV (sensory)

4. General visceral afferent- solitary nucleus (sensory)
5. Special visceral afferent- base of tongue to solitary nucleus (taste)

Question 24

What are the 2 parts of CN11 and where are they from

Answer 24

Cranial (nucleus ambiguous)

Spinal (spinal nuclei in c1-5)

Question 25

How does the cranial part of CN11 form and where does it go to inn

Answer 25

arrises from roots from medulla that unite w spinal part before passing thru jugular foramen

-once exiting skull will joint w vagus nerve to supply mm of the palate, pharynx and larynx

Question 26

How does the spinal part of CN11 form and where does it go to inn

Answer 26

arrises from upper 5 cerv segments, goes up thru foramen magnum to join w cranial part and then supplies scm and traps

Question 27

What is supplied by CN12

Answer 27

Supplies all intrinsic and extrinsic mm of tongue MINUS the palatoglossus (by vagus)

Question 28

what do special visceral efferents supply and what are the mm from each of the 4 arches

Answer 28

mm from the branchial (pharyngeal) arches

Arch 1- CNV
Arch 2- CN7
Arch 3- Stylopharyngeus
Arch 4- CNX (mm of pharynx/larynx)