Head and neck: cranial nerves II

Question 1

CN VII facial nerve: enters/ exits CNS

Answer 1

btw pons and medulla

Question 2

CN VII facial nerve: enters/ exits skull

Answer 2

• internal acoustic meatus -> facial canal -> stylomastoid foramen

Question 3

CN VII facial nerve: site of cell bodies

Answer 3

• SVE (BE): pons
• SA: geniculate ganglion
• GVE: presynaptic fibres (pons), postsynaptic (pterygopalatine and submandibular ganglia)

Question 4

CN VII facial nerve: list 2 main roots

Answer 4

• intermediate nerve (sensory, nervus intermedius)

- motor root

Question 5

CN VII facial nerve: intermediate nn fibres

Answer 5

• GSA: sensory from ext acoustic meatus
• SA: taste ant 2/3 tongue
• GVE: parasymp secretomotor (lacrimal gland, sublingual salivary, mucous membranes of nasal cavity glands, hard and soft palate)

Question 6

CN VII facial nerve: what branch supplies taste ant 2/3 of tongue

Answer 6

• chorda tympani (petrotrympanic fissure)

Question 7

CN VII facial nerve: motor root fibres

Answer 7

• SVE: mm facial expression and scalp, stapedius, post belly of digastric, stylohyoid mm

Question 8

CN VII facial nerve: within facial canal gives what nn

Answer 8

• greater petrosal
• n to stapedius
• chorda tympani

Question 9

CN VII facial nerve: after exiting stylomastoid foramen, it gives-

Answer 9

• temporofacial
• cervicofacial
• digastric branch
• post auricular

Question 10

CN VII facial nerve: once entering parotid gland name branches

Answer 10

• temporofacial, cervicofacial both:
• temporal
• zygomatic
• buccal
• marginal mandibular
• cervical

Question 11

CN VIII vestibulocochlear nerve: enters/ exits CNS

Answer 11

btw pons and medulla

Question 12

CN VIII vestibulocochlear nerve: enters/ exits skull

Answer 12

• internal acoustic meatus

Question 13

CN VIII vestibulocochlear nerve: site of cell bodies

Answer 13

• vestibular ganglion (vestibular n)

- spiral ganglion (cochlear n)

Question 14

CN VIII vestibulocochlear nerve: function SSA

Answer 14

• vestibular n: equilibrium

- cochlear: hearing

Question 15

eg. vestibular neuritis, labryinthitis, acoustic neuroma

Answer 15

• vestibular neuritis: inflammation of vestibular n -> compression of structures
• labyrinthitis: similar
• acoustic neuroma: tumour growth, also compression

Question 16

CN IX glossopharyngeal nerve: enters/ exits CNS

Answer 16

medulla

Question 17

CN IX glossopharyngeal nerve: enters/ exits skull

Answer 17

• jugular foramen

Question 18

CN IX glossopharyngeal nerve: site of cell bodies

Answer 18

• SVE: medulla
• GVE: presynaptic (medulla), postynaptic (otic ganglion)
• GSA: inf ganglion
• GVA: sup ganglion
• SVA: inf ganglion

Question 19

CN IX glossopharyngeal nerve: function- SVA

Answer 19

• sense of taste post 1/3 tongue

Question 20

CN IX glossopharyngeal nerve: function- GSA

Answer 20

sensory from mucosa of:

• palatine tonsil and oropharynx
• post 1/3 of tongue
• auditory tube (pharyngotympanic), middle ear

Question 21

CN IX glossopharyngeal nerve: function- GVA

Answer 21

• sensory from carotid body and sinus

Question 22

CN IX glossopharyngeal nerve: function- GVE

Answer 22

• parasympathetic

- stimulate secretion of parotid salivary gland

Question 23

CN IX glossopharyngeal nerve: function- SVE (BE)

Answer 23

• stylopharyngeus (mm from 3rd pharyngeal arch)

Question 24

CN X vagus nerve: enters/ exits CNS

Answer 24

medulla

Question 25

CN X vagus nerve: enters/ exits skull

Answer 25

- jugular foramen

Question 26

CN X vagus nerve: sites of cell bodies

Answer 26

- SVE: medulla - GVE: presynaptic (medulla), postsynaptic fibres (neurons close to/ within viscera innervated) - GSA: sup ganglion - GVA: sup ganglion - SVA: inf ganglion

Question 27

CN X vagus nerve: function- SVE

Answer 27

- constrictor mm of pharynx (except stylopharyngeus) - intrinsic mm of larynx - mm of palate (except tensor veli palatini) - skeletal mm (striated) in upper 2/3 esophagus

Question 28

CN X vagus nerve: function- GVE

Answer 28

- cardiac mm | - smooth mm of airways, digestive tract

Question 29

CN X vagus nerve: function- GSA

Answer 29

- sensory from auricle, ext auditory meatus, dura mater in post cranial fossa

Question 30

CN X vagus nerve: function- GVA

Answer 30

- sensation from base of tongue, pharynx, larynx, airways, heart, oesophagus, stomach, intestine (to L colic flexure)

Question 31

CN X vagus nerve: function- SVA

Answer 31

- taste from epiglottis and palate

Question 32

don't confuse phrenic w vagus nn:

Answer 32

- vagus: more medial, w common carotid aa (L loops around arch of aorta) - phrenic: btw ant/ middle scalenes

Question 33

CN XI accessory nerve: enters/ exits CNS

Answer 33

- cranial root: medulla | - spinal root: upper spinal cord

Question 34

CN XI accessory nerve: enters/ exits skull

Answer 34

- jugular foramen (cranial and spinal roots) | - cranial root leaves spinal to join vagus

Question 35

CN XI accessory nerve: site of cell bodies

Answer 35

- cranial: medulla | - spinal: spinal cord

Question 36

CN XI accessory nerve: function

Answer 36

- cranial root: mm to pharynx, larynx | - spinal root: motor to trapezius, sternomastoid mm

Question 37

CN XI accessory nerve: runs in neck

Answer 37

- btw int carotid aa and int jugular v, obliquely to trapezius

Question 38

CN XII hypoglossal nerve: enters/ exits CNS

Answer 38

- medulla

Question 39

CN XII hypoglossal nerve: enters/ exits skull

Answer 39

- hypoglossal canal

Question 40

CN XII hypoglossal nerve: site of cell bodies

Answer 40

- medulla

Question 41

CN XII hypoglossal nerve: function

Answer 41

- motor to intrinsic/ extrinsic mm of tongue (except palatoglossus)

Question 42

CN XII hypoglossal nerve: how does it run

Answer 42

- after hypoglossal canal runs along mandible