CSD429 exam 1

scala vestibuli

uppermost tube, connects to oval window

what do you see during an otoscopy

mesotympano & malleus

how to overcome impedence mismatch

pinna amplifies sound, TM vibrates and converts acoustic energy to mechanical vibration, lever action of ossicles delivers force to oval window, areal ratio of TM and stapes increases pressure

outer hair cells

furthest from modiolus, 3 rows, attached at top and bottom, source of otoacoustic emissions

inner hair cells

closest to modiolus, single row

reisner’s membrane

separates scala vestibuli and scala media

stapedius

shorter of 2 muscles, more powerful of 2 muscles, pulls stapes footplate away from oval window

tensor tympani

larger of 2 muscles, less powerful of 2 muscles, pulls manubrium away from TM

shrapnell’s membrane

small part of pars flaccida w/ no connective tissue, ruptures first with pressure

pediatric audiologist

works in children’s hospital, excellent counseling skills, aural re/habilitation

examples of HL impact on children

impaired speech/language development, impaired academic performance, impaired social/emotional development, parent/child bonding, time taken away from siblings

functions of TM

transmit sound to ossicles, compensate for loss of sound energy (areal ratio)

function of oval window

sets forth traveling wave in cochlea

function of round window

relieves pressure wave, 180 degrees out of phase with oval window

function of middle ear muscles

protect inner ear from loud sounds, frequency selection, maintain maximum tension, vary inner ear fluid pressure

Eustachian tube

mucosal lined tube that runs from the middle ear to nasopharynx, regulates pressure in middle ear, drains fluid

function of ossicular chain

transmit mechanical energy, amplify sound, route energy to oval window