LEC65: Our Ears

Question 1

greek, latin, olde english, pinna for ear?

Answer 1

greek: oto (otic)
latin: auris (auricular)

olde english: eare

pinna: from latin, feather, wing, fin

Question 2

identify the temporal bone

Answer 2

Question 3

parts of the temporal bone?

Answer 3

squamosal

zygomatic

mastoid

tympanic

Question 4

what is within temporal bone?

Answer 4

sensory organs for balance and hearing

Question 5

what connects to styloid process of temporal bone?

Answer 5

stylyhyoid ligament

stylomandibular ligament

styloglossus m (XII)

stylohyoid m (VII)

stylopharyngeus m (IX)

Question 6

what is different about a baby’s temporal bone?

Answer 6

no mastoid process - it’s a developmental feature

Question 7

where does internal acoustic meatus open?

Answer 7

into petrous part of temporal bone

Question 8

which region of skull is temporal bone in?

Answer 8

middle cranial fossa

Question 9

what is within the mastoid process here?

Answer 9

mastoid air cells

neumatized bone in the mastoid process

bone lessens with aging there - normal - air circulates. but can have infection spread here.

Question 10

what provides sensory innervation to inner ear canal? nerve and fiber type

what other nerves do you find in the inner ear canal?

Answer 10

GSA of CN VII, facial n

also see vestibular nerve, cochlear nerve - balance

Question 11

if facial nerve is knocked out when exits internal acoustic meatus, what is lost?

Answer 11

all function of VII

Question 12

if VII is knocked out distal to greater petrosal nerve, what remains / is lost?

Answer 12

retain lacrimal gland GVE

lose sublingual/submandibular gland GVE

lose taste to anterior 2/3 tongue SVA

lose facial expression SVE

Question 13

if VII is knocked out distal to chorda tympani, what is retained/lost?

Answer 13

retain:

lacrimal GVE (greater petrosal n)

sensation of inner ear GSA (n to stapedius)

taste to anterior 2/3 tongue SVA submandibular, sublingual glands’ GVE (chorda tympani)

lose:

facial expression SVE

Question 14

sensory ganglion of facial n?

Answer 14

geniculate ganglion

Question 15

where do motor branches of facial n traverse?

Answer 15

across parotid gland

then span out, do mm of facial expression

Question 16

what are our 6 ears?

Answer 16

external, middle, inner on each side of the head

Question 17

boundaries of each part of ear?

Answer 17

external: pinna - canal - tympanic membrane
middle: tympanic membrane - oval window
inner: deep w/in crevices of petrous

Question 18

parts of external ear?

Answer 18

1) auricle aka pinna - what we see on outside
2) external acoustic meatus - external ear canal, leads to tympanic membrane

Question 19

ID: helix, anti-helix, tragus, concha, pinna

Answer 19

Question 20

first arch syndrome re: ear? what might result?

Answer 20

poor developed meckel’s cartilage

poorly developed pinna

mandible underdeveloped

Question 21

functions of external ear?

Answer 21

capture, direct, amplify sound

dissipate heat

communicate / mood signaling

Question 22

what provides auricular sensation?

Answer 22

V - auriculotemporal branch

VII - posteiror canal wall

IX - medial, inner part of tympanic membrane (via tympanic n)

X - most of ear canal, part of outer surface of tympanic membrane (auricular br)

C2, C3 - greater auricular n

C2 - lesser occipital n

Question 23

where is sexual stimulation on ear? sexual suppression?

Answer 23

Question 24

what causes cauliflower ear?

Answer 24

blows, damage that separate cartilage of pinna from surrounding tissue

tissue fills with fluid so difficult for blood or other serous fluid to escape

Question 25

wax function in ears?

Answer 25

catches things coming in works w/ sebaceous gland, keeps tympanic membrane moist, lubricated

Question 26

Answer 26

hairs sticking in to sebaceous glands ceruminous glands v important to give moistening

Question 27

what is otitis externa

Answer 27

common, inflammation with external ear

Question 28

why might you cough when inserting something into the ear?

Answer 28

because major innervation is from a branch of X, vagus this is vagal response

Question 29

what is otomorphology

Answer 29

study of the appearnce of the external ear every person's is different can be used as a fingerprint substitute

Question 30

where is middle ear? what is its main property?

Answer 30

air-filled space from tympanicmembrane laterally to lateral wall of inner ear medially communicates w/ mastoid air cells & pharyngotympanic (eustachian) tube

Question 31

identify: pinna, ear canal, eardrum, middle ear, inner ear, eustachian tube

Answer 31

Question 32

ossicles of middle ear?

Answer 32

malleus incus stapes

Question 33

what is tympanic membrane a remnant of?

Answer 33

pharyngeal pouch of 1st branchial arch

Question 34

identify chorda tympani, incus, handle of malleus

Answer 34

Question 35

identify malleus

Answer 35

Question 36

what is the difference

Answer 36

Question 37

what is otitis media

Answer 37

build up of pressure in the middle ear, causes ear infection very painful

Question 38

what might chronic otitis media cause?

Answer 38

tear in the tympanic membrane (ear drum) may effect malleus, may effect entire hearing mechanism, may have scaring on tympanic membrane

Question 39

muscles of inner ear, their innervation, branchial arch derivation, function?

Answer 39

1) tensor tympani - V - arch 1 - dampen sounds, such as those produced from chewing 2) stapedius - VII - arch 2 - stabilize the stapes

Question 40

how does sound move from outside \> inside?

Answer 40

sound through ear canal \> hits tympanic membrane tympanic membrane vibrates, virbation \> malleus malleus passes vibration to incus, passes virbation to stapes \> voal window \> inner ear fluids

Question 41

what is smallest bone in human body?

Answer 41

stapes!

Question 42

branchial arch of upper portion of malleus and incus?

Answer 42

branchial arch I

Question 43

branchial arch of lower part of malleus and incus?

Answer 43

branchial arch II

Question 44

branchial arch of arcus of stapes?

Answer 44

arch II

Question 45

nerve of branchial arch II?

Answer 45

chorda tympani

Question 46

what are the joints between the ossicles called? what type of joints?

Answer 46

synovial joints: 1) incudomaller (malleus-incus) 2) incudostapedeal (incus-stapes)

Question 47

what is otosclerosis? what's result?

Answer 47

if footplate of stapes becomes fused to oval window lose hearing

Question 48

what part of eustachian tube enters middle ear?

Answer 48

bony portion of eustachian tube \> middle ear, at nasopharynx, at rear of nasal cavity

Question 49

components of eustachian tube?

Answer 49

bony and cartilagenous portions

Question 50

function of eustachian tube?

Answer 50

does aeration- equilibration of pressure in middle ear

Question 51

describe difference between child/adult eustachian tube

Answer 51

child's tube is horizontal, so children get infection easily adults have more vertical tubes, so less likely to get otisis media

Question 52

most common childhood ailment in the US?

Answer 52

middle ear disease, otitis media

Question 53

areas of inner ear?

Answer 53

1) bony cavities (bony labyrinth) 2) membranous ducts & sacs (membranous labyrinth)

Question 54

what does bony labyrinth contain?

Answer 54

vestibule, semicircular canals, cochlea cavities lined w/ periosteum, contain perilymph

Question 55

what does membranous labyrinth contain?

Answer 55

semicircular ducts, cochlear duct, utricle, saccule spaces lined w/ endolymph

Question 56

where is inner ear lodged?

Answer 56

deep within petrous bone

Question 57

interaction btwn oval and round windows?

Answer 57

foot of stapes pushe in on oval window \> helps push fluid around round window pushes out, opposes action

Question 58

functional elements of inner ear?

Answer 58

hair cells

Question 59

what is on top of hair cells of inner ear? fxn?

Answer 59

stereocilia highly sensitive, so pick up pressurs and convey info back to brain have these in semicircular canal, cochlea

Question 60

how many semicircular canals?

Answer 60

3 on each side of head

Question 61

types of hearing loss

Answer 61

1) conductive hearing loss 2) sensorineural hearing loss

Question 62

what is conductive hearing loss caused by, how does it present?

Answer 62

caused by piercing, related activities failure in efficient conduction of sound waves thru outer ear, tympanic membrane, or middle ear

Question 63

what is sensorineural hearing loss caused by, what does it damage?

Answer 63

caused by damage to hair cells - ie rock concerts - or diseas or brain trauma damages: cochlear n, inner ear hair cells, and/or brain

Question 64

nerves \> inner ear?

Answer 64

VII, facial VIII, vestibulocochlear

Question 65

presbycusis?

Answer 65

major presentaiton of sensorineural hearing loss age-related hearing loss extremely common

Question 66

how do cochlear implants work?

Answer 66

insert into cochlea stimulates damaged hair cells \> stimulates back to nerves

Question 67

vestibular system diseases examples? what do we know about them?

Answer 67

balance disorder such as meniere's disease, labyrinthitis, vertigo know fluid compositions in perilymph and endolymph are problematic but don't understand disease process

Question 68

what is our oldest evolutionary sense?

Answer 68

balance