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Question 2

outer ear

Answer 2

elastic cartilage, thin skinindividually locate sound in vertical plane and together in horizontal plane

Question 3

external auditory meatus

Answer 3

elastic cartilage externally and bone deeperkeratinized stratified squamous liningceruminous glands -> wax secretingamplifies sound and protects tympanic membrane

Question 4

Tympanic membrane

Answer 4

externally -> internalstratified squamous -> collagenous and elastic fibers radial layer -> circular layer -> simple squamous internal lining

Question 5

Middle Ear

Answer 5

Ossicles (malleus, incus, stapes)lined with simple squamous and cuboidaltensor tympani, stapedius skeletal musclesauditory tube

Question 6

Ossicles

Answer 6

malleus, incus and stapestransmit sound from air to fluidstapes footplate on oval window (via annular ligament)

Question 7

Tensor tympani and stapedius

Answer 7

pull on malleus and stapes respectivelydampen loud noise

Question 8

Bony labyrinth

Answer 8

filled w/ perilymphcontains membranous labyrinth

Question 9

membranous labyrinth

Answer 9

filled w/ endolymphcontains vestibular and auditory portions

Question 10

vestibular portions

Answer 10

semicircular canalsutricle saccule

Question 11

cochlea

Answer 11

auditory portion2.5 coils of 3 scalae (media, tympani and vestibuli) around bony axis modiolus

Question 12

scala media

Answer 12

endolymph filledhouses organ of cortibound basally by basilar membranelaterally by stria vascularisapically by vestibular (Reissners) membrane

Question 13

scala vestibuli

Answer 13

perilymph from oval window and continuous with scala tympani at helicotrema

Question 14

scala tympani

Answer 14

from scala vestibuli to round window

Question 15

organ of corti

Answer 15

sensor of sound vibrationsinner and outer hair cells held by phalangeal cells (inervates hair cell also)sound wave displace basilary membrane hear -> shear force on hair cells -> depolarization -> signal transmission

Question 16

Semicircular canal

Answer 16

3 arch shaped tubes full of endolymphampulla at one end and connected to utricle at each endampulla is sensory portion

Question 17

Crista ampullaris

Answer 17

consists of sensory hair cells and supporting cellshair cells covered by gelatinous sheath secreted by planum semilunatum -> cupula cupula moves with endolymph in response to angular acceleration -> shearing force on hair cells

Question 18

Type 1 hair cells

Answer 18

flask shaped, sitting in large afferent nerve processeach has 1 kinocillium (microtubule core) and 40-80 stereocilium (actin core)stereocilim tethered together

Question 19

Type 2 hair cells

Answer 19

columnar and mostly efferent nerve innervation1 kinocillium and many stereocilium (tethered together)

Question 20

utricle

Answer 20

contains horizontal macula

Question 21

saccule

Answer 21

contains vertical macula

Question 22

macula

Answer 22

sensory epithelium of sacula and utricle contain both type 1 and 2 hair cells gelatinous covering contains otoliths (adds inertia) detects linear acceleration

Question 23

endolymphatic duct and sac

Answer 23

extension of membranous labyrinth nearing meningesmay secrete into endolymph and absorb endolymph

Question 24

endolymph

Answer 24

high K and low Nain membranous labyrinth

Question 25

perilymph

Answer 25

High Na and low Kin bony labyrinth

Question 26

inner hair cells

Answer 26

In organ of cortilike type 1 hair cells - many afferent -> sends signal back to brainkinocilium lacks microtubule

Question 27

outer hair cells

Answer 27

in organ of cortiresemble type 2 hair cells - mostly efferentcontains prestin protein -> contracts hair cells (modifying/amplifying sound for inner hair cells)

Question 28

interdental cells

Answer 28

secrete gelatinous sheath of the organ of cortiin spiral lamina (contains collagen type 2 and keratin)

Question 29

stria vascularis

Answer 29

lateral border of organ of Cortimarginal cells of stria vasc. provide ion pumping force to form endolymph