Ear

Question 1

what bone in the skull is the ear associated with

Answer 1

petrous temporal bone

Question 2

what are the 3 parts of the ear?

Answer 2

external, middle and internal

Question 3

what do the middle and external ear do

Answer 3

transfer sound to the internal ear

Question 4

what separates the external and middle ear

Answer 4

tympanic membrane

Question 5

what does the pharyngotympanic tube join

Answer 5

middle ear to nasopharynx

Question 6

what is the auricle made of

Answer 6

elastic cartilage

Question 7

what is the main function of the auricle

Answer 7

support the ear, catch and funnel sound to external acoustic meatus

Question 8

what are the main parts of the auricle

Answer 8

helix, lobule, tragus, concha

Question 9

what is the sensory innervation of the auricle

Answer 9

great auricular (for medial surface, back of ear) and auriculotemporal (for anterior ear, tragus)

Question 10

what is the external acoustic meatus made of

Answer 10

cartilage and bone

Question 11

what epithelium is in the external acoustic meatus and what does it contain

Answer 11

stratified squamous
hair follicles, glands, ceruminous glands secreting ear war, blood vessels, nerves

Question 12

how is the tympanic membrane held within the temporal bone

Answer 12

by a fibrocartilaginous ring

Question 13

what is the tympanic membrane covered in

Answer 13

skin externally and mucous membranes internally

Question 14

why does the tympanic membrane move

Answer 14

in response to air vibrations passed to it through the EAM

Question 15

once the tympanic membrane moves, where does this movement go to

Answer 15

transmitted by ossicles through middle ear and to the internal ear

Question 16

how can the tympanic membrane be examined

Answer 16

by an otoscope

Question 17

what does the cone of light mean when it is seen on an otoscope

Answer 17

that the tympanic membrane is healthy and there is no fluid accumulation

Question 18

what is the middle ear called

Answer 18

tympanic cavity

Question 19

what does the middle ear contain

Answer 19

ossicles and muscles, pharyngotympanic tube

Question 20

what are the ossicles

Answer 20

malleus, incus and stapes

Question 21

what are the 2 muscles in the middle ear

Answer 21

tensor tympani and stapedius

Question 22

what attaches to the tympanic membrane

Answer 22

handle of malleus

Question 23

what attaches to the oval window

Answer 23

base of stapes

Question 24

what do the ossicles do with sound

Answer 24

increase the force and decrease the amplitude

Question 25

why do the ossicles increase force and decrease amplitude of sound

Answer 25

because the inner ear is fluid filled and it needs to change the sound to match the fluid waves

Question 26

what do the small muscles in the middle ear do

Answer 26

dampen/resist movement of ossicles and have protective function over the ear and tympanic membrane

Question 27

where does the tensor tympani insert into

Answer 27

handle of malleus

Question 28

what does the tensor tympani do

Answer 28

pulls handle of malleus medially which tenses the tympanic membrane reducing the amplitude of oscillations (prevent damage)

Question 29

what does the stapedius do

Answer 29

pulls stapes posteriorly reducing range of oscillations and excessive movement of stapes

Question 30

what is the stapedius innervated by

Answer 30

nerve to stapedius

Question 31

what is the tensor tympani innervated by

Answer 31

mandibular division of trigeminal nerve

Question 32

what is the pharyngotympanic tube made of

Answer 32

initially bone and then cartilages

Question 33

what is the function of the pharyngotympanic tube

Answer 33

pressure equalisation between middle ear and atmospheric pressure and replenishes air of middle ear

Question 34

what can occur as a result of the pharyngotympanic tube

Answer 34

middle ear infections

Question 35

what nerves enter the internal acoustic meatus

Answer 35

facial nerve and vestibulocochlear

Question 36

what is the course of the facial nerve

Answer 36

internal acoustic meatus - facial canal (greater petrosal given off) - chorda tympani and nerve to stapedius given off

Question 37

what blood vessels run close to the middle ear

Answer 37

ICA and IJV

Question 38

the roof of the ear is very thin between middle cranial fossa and ear, what does this mean

Answer 38

infection spread to cranial cavity severe infection erodes the bone towards vascular and can affect ICA and IJV meaning systemic spread of infection

Question 39

what are middle ear infections called

Answer 39

otitis media

Question 40

what can chronic infection in the middle ear cause

Answer 40

damage to the ossicles - conductive deafness infection spread to mastoid cells (mastoiditis)

Question 41

how is mastoiditis treated and what do you need to be aware of

Answer 41

antibiotics but mainly surgery so be aware of facial nerve

Question 42

how is the ear connected to the mastoid

Answer 42

through mastoid antrum

Question 43

what is conductive hearing loss

Answer 43

condition of sound production through ossicles causing deafness

Question 44

what is otitis media with effusion

Answer 44

build up of fluid behind tympanic membrane which restricts movement of ossicles

Question 45

how do you fix otitis media

Answer 45

grommets

Question 46

what is contained in the bony labyrinth of the inner ear

Answer 46

vestibule, cochlea, semi-circular canals

Question 47

what fluid does the bony labyrinth contain

Answer 47

perilymph

Question 48

what is the structure of the inner ear

Answer 48

bony labyrinth containing membranous labyrinth

Question 49

what fluid does the membranous labyrinth of inner ear contain

Answer 49

endolymph

Question 50

what does endolymph do

Answer 50

stimulate organs for balance and hearing

Question 51

what bone contains the inner ear

Answer 51

otic capsule

Question 52

what is the function of the cochlea

Answer 52

hearing

Question 53

what is the function of the vestibule

Answer 53

balance

Question 54

what is the function of the semi-circular canals

Answer 54

balance (communicate with vestibule)

Question 55

what signal does the vestibulocochlear nerve convey

Answer 55

motion and hearing

Question 56

where does CNVIII divide

Answer 56

lateral end of internal acoustic meatus

Question 57

what are the 2 divisions of CNVIII

Answer 57

vestibular and cochlear

Question 58

what does the cochlear nerve supply

Answer 58

cochlea

Question 59

what does the vestibular nerve supply

Answer 59

semi-circular canals, saccule and utricle (vestibule)

Question 60

what can damage to the cochlear nerve result in

Answer 60

hearing loss (either neural or conductive)

Question 61

what does the cochlear nerve do

Answer 61

receptor of auditory stimuli

Question 62

what does the vestibular nerve do

Answer 62

balance and equilibrium

Question 63

what can damage to the vestibular nerve do

Answer 63

ataxia, vertigo and nausea