Ear

Question 1

Path of sound waves through ear

Answer 1

External auditory canal
Tympanic membrane
Malleus
Incus
Stapes
Oval window
Fluid of inner ear
Fluid filled cochlea
Sensory hair cells on membrane (organ of corti) of spinal organ

Question 2

Tympanic membrane

Answer 2

fibrous membrane separating external auditory canal from middle ear

Question 3

The ossicles: malleus, incus, stapes

Answer 3

transmit sound from tympanic membrane to oval window

Question 4

The oval window

Answer 4

connects ossicles to scala vestibule-perilymph

Intersection of middle and inner ear

Question 5

The round window

Answer 5

as stapes footplate moves into oval window, round window moves out

allows movement of fluid within the cochlea leading to movement of cochlea inner hair cells

Question 6

the auditory tube (eustachian)

Answer 6

connects nasopharynx to middle ear - equalising pressure

Question 7

external auditory canal

Answer 7

lined by skin that produces ear wax - viscous secretions from sebaceous glands, less viscous from apocrine, sheds layers of skin (keratin), fatty acids, alcohol, squalene, cholesterol.

Question 8

traves

Answer 8

conveyer belt process of epithelial migration aided by jaw movements.

migrate from umbo to entrance of ear canal

Question 9

what is the umbo?

Answer 9

centre of the tympanic membrane

Question 10

function of the chorda tympani

Answer 10

taste to ant. 2/3 tongue

parasym to subman and subling

Question 11

middle ear

Answer 11

filled with air
respiratory epithelium
liable to infection of URTI
connected antero-inferiorly to the nasopharynx

Question 12

middle ear is connected posteriorly to

Answer 12

mastoid air cells

through aditus to mastoid antrum

Question 13

where does internal jugular lie relative to middle ear?

Answer 13

inferior

Question 14

where does IC art lie relative to middle ear?

Answer 14

ant.

pulsatile tinnitus

Question 15

how do chorda tympani and facial canal lie relative to middle ear?

Answer 15

traverses it

Question 16

path of chorda tympani and facial nerve

Answer 16

`through temporal bone via internal auditory tube and winds around middle ear bones

Question 17

tensor tympani - nerve innervation and why

Answer 17

V3 trigeminal

contractions pulls handle of malleus medially

Question 18

stapedius - nerve innervation and why

Answer 18

pull stapes posteriorly and prevents excessive vibrations

Question 19

where is the inner ear?

Answer 19

within the petrous temporal bone filled with perilymph

Question 20

within the cavity of the inner ear there is a sac?

Answer 20

epithelial sac, membraneous labyrinth, filled with fluid called endolymph

Question 21

Receptors within membraneous labyrinth

Answer 21

Maculae - vestibular receptors
Christae ampullaris - vestibular receptors
Spiral organ (organ of corti) - auditory receptors

Question 22

maculae location

Answer 22

utricle and saccule

balance - sensory info about static position of head in space

Question 23

christae ampullaris location

Answer 23

semicircular ducts in ampulla

change of direction and rate of movement of head

Question 24

structural similiarities between maculae and christae ampullaris

Answer 24

same morphological type
single layer of columnar cells cont. with simple cuboidal epithelium
hair cells have numerous stereocilia

Question 25

nystagmus

Answer 25

rapid involuntary eye movements

Question 26

vertigo

Answer 26

dizziness and abnormal perception of motion

Question 27

organ of corti

Answer 27

specialised region of wall of cochlear duct

part of membraneous part within bony cochlea

Question 28

the bony cochlea spirals around the

Answer 28

spiral ganglion made of cell bodies of 1st order auditory neurons

Question 29

where does high frequency go

Answer 29

near oval window - base

Question 30

where does low frequency go

Answer 30

helicotrema - apical end

Question 31

first order sensory join what fibres to where

Answer 31

cochlear nerve to vestibulocochlear to internal acoustic meatus

Question 32

conduction deafness

Answer 32

sounds cannot pass freely to inner ear

Question 33

sensorineural deafness

Answer 33

damage to hair cells in cochlear - irreversible