Anatomy: ear and facial nerve

Question 1

which arteries perfuse the cranial cavity

Answer 1

ICA, vertebral ro form circle of willis

Question 2

which arteries perfuse the face

Answer 2

ICA and ECA

Question 3

which arteries perfuse the neck

Answer 3

ECA and subclavian artery

Question 4

branches of ECA from proximal to distal (some anatomists like freaking out poor medical students)

Answer 4

superior thyroid, ascending pharyngeal, lingual, facial , occipital, posterior auricular, maxillary, superficial temporal

Question 5

what cranial nerve descends posteriorly to carotid sheath

Answer 5

CNX - vagus

Question 6

how to post-synaptic nerve fibres course to their targets

Answer 6

peri-arterial plexuses

Question 7

where does ENT venous supply ultimately drain too

Answer 7

internal jugular

Question 8

what outflow is parasympathetic

Answer 8

craniosacral

Question 9

where pre-ganglionic parasympathetic axons originate from and where do the postganglionic go

Answer 9

CNIII (oculomotor) –> ciliary G. CNVII (facial) –> pterygopalatine G. CNIX (glossopharyngeal) –> submandibular G. CNX (vagus) –> Otic G

Question 10

where does lymphatics of ENT drain

Answer 10

right or left lymphatic duct

Question 11

what node does the palatine tonsil drain to

Answer 11

jugulo-digastric node

Question 12

what is the function of the pinna/ auricle (external ear)

Answer 12

collect soundwaves and funnels them to external acoustic meatus (ear hole)

Question 13

what nerve runs with superficial temporal artery

Answer 13

auriculotermporal nerve CNV3

Question 14

where is the tympanic cavity

Answer 14

middle ear

Question 15

what is the function of tympanic cavity (2)

Answer 15

conduct soundwaves towards fluid filled cavaties of the inner ear. controls ossicles

Question 16

what are the ossicles for and what are they called (lateral to medial)

Answer 16

bone conduction mechanism of hearing. Malleus, incus stapes

Question 17

what joints are in-between ossicles

Answer 17

synovial

Question 18

what ligaments are malleus and incus suspended from

Answer 18

tegmen tympani

Question 19

where is the oval window

Answer 19

in the otic capsule (stapes and cochlea)

Question 20

what is the tympanic membrane

Answer 20

eardrum

Question 21

what are the 2 muscles in the middle ear, what innervates them and what do they do

Answer 21

tensor tympani muscle (CNv3), strapedius muscle (CNVII). dampen sound

Question 22

where are the 2 middle ear muscles

Answer 22

tensor tympani muscle = handle of malleus. strapedius muscle = neck of stapes.

Question 23

what do the palate muscles do

Answer 23

open eustachian tube to equalise pressure

Question 24

where does the eustachian tube connect the middle ear to, what is its sensory nerve

Answer 24

nasopharynx (CNIX)

Question 25

what can happen with an infection in nasopharynx

Answer 25

referred pain to ear.

Question 26

what is the general sensory nerve of tympanic cavity, via what plexus

Answer 26

CNiX, tympanic --> lesser petrosal nerve

Question 27

what and where is the mastoid antrum. what is infection of this cause and what is a risk. what nerve is close to it

Answer 27

continuous with tympanic cavity and lined with mucous. Mastoiditis --> osteomyelitis. CNVII

Question 28

where is the otic capsule. what and where are the 2 labyrinths. what lymph do they have

Answer 28

inner ear, temporal bone. bony labyrinth in cavity of otic capsules, perilymph. membranous labyrinth in bony labyrinth, endolymph .

Question 29

describe how sound is transmitted to brain.

Answer 29

1) tympanic membrane. 2) ossicles vibrate. 3) travels through oval window. 4) pressure waves in perilymph. 5) basilar membrane vibrates and hair cells in cochlea (organ of corti) make AP's. 6) cochlear nerve (CNVIII) transmits to brain. 7) pressure waves dampened at round window

Question 30

what is the organ of sound and where is it detected

Answer 30

organ of corti, basilar membrane of cochlea

Question 31

what is the cochlear duct suspended by and what does it divide into 2 parts.

Answer 31

spiral ligament. cochlear canal into scala tympani and scala vestibuli.

Question 32

what part of the ear is affected in conductive hearing loss and sensorineural hearing loss

Answer 32

conductive = outer/ middle. sensorineural = inner ear.

Question 33

where is the vestibular apparatus and what is it for

Answer 33

part of otic capsule, next to cochlear. responsible for balance and head movement.

Question 34

in vestibular apparatus what are hair cells moved by and where does it lie (what labyrinth)

Answer 34

endolymph, membranous

Question 35

in vestibular apparatus what detects angular movement change and what detects linear.

Answer 35

semicircular ducts detect angular movement. utricle (horizontal) and saccule (vertical) detect linear movement.

Question 36

what are the names of the semicircular canals. how do they detect head movement.

Answer 36

anterior, posterior and lateral. ampullae have hair cell clusters which detect movement and depolarise

Question 37

describe the course of the vestibulocochlear nerve CNVIII

Answer 37

leaves at pons and travels through internal acoustic meatus. where it splits to cochlear nerve (from spiral ganglion) and vestibular nerve.

Question 38

what passes through internal acoustic meatus

Answer 38

Facial nerve (CNVII), vestibulocochlear (CNVII). labyrinthine artery and veins (form circle of willis).

Question 39

what does facial nerve supply generally in head and neck.

Answer 39

lacrimal gland and some in nasal cavity. taste buds (ant 2/3rd) and salivary glands (sublingual and submandibular), muscles of facial expression

Question 40

what is the facial nerves course.

Answer 40

leaves at brainstem and enters internal acoustic meatus. runs close to ear and leaves temporal bone through stylomastoid foramen.

Question 41

what are the temporal branches of the facial nerve

Answer 41

nerve to stapedius and greater petrosal nerve

Question 42

what is the chorda tympani

Answer 42

branches from facial nerve in facial canal, passes between incus and malleus, attaches to CNV3 and gets taste from ant 2/3 of tongue.

Question 43

what is the taste supply to the ant 2/3 of the tongue

Answer 43

facial nerve CNVII

Question 44

what is sensory supply to ant 2/3rd tongue

Answer 44

trigeminal CNV3

Question 45

what are the 4 types of taste buds

Answer 45

follate, vallate, fingiform (taste buds). filiform (sensory)

Question 46

what supplies post 1/3 of tongue

Answer 46

vertical part, glossopharyngeal (CNIX)