Ear Lab

pinna

funnels sound into external auditory canal

external auditory meatus

conducts sound waves to timpatic membrane

tympanic membrane

conducts sound from external auditory canal to ossicles

ossicles

amplifies sound / carries sounf from tymptic membrane to oval window

pharyngotympanic tube (eustachian)

tube down - equalizes pressure in middle ear

inner ear

bony labyrinth / membranous labyrinth

cochlea

snail shell - contains receptors for hearing

oval window

movement initiates movemnt of fluid within cochlea - stapes attached

round window

counteracts movement of oval (negataes) - maintains volume - pressure changes of cochlear fluid

cochlear branch

sensory info for hearing equilibrum

vestibule

equilibrium / balance

utricle

closer to semi circular canal - gray bulb top -gravitational equilibrium

saccule

closer to cochlea - gray buld bottom - gravitational equilibrium

anterior semiC.C

touch cochlea througth - rotational equilibrium

posterior semiCC

Faces pinna - rotational equilibrium

lateral semiCC

faces out - rotational equilibrium

weber test

tuning fork on forhead - CHL: lateralization to affected ear (blockage or damaged outer/middle ear) - SHL: lateralized to unaffeted ear (inner ear nerve damage)

rinnie test

tuning fork behinf ear - AC>BC = normal - BC>AC = abnormlal

conductive HL

loss up to cochlea BC>AC

Sensorineural HL

hearing loss cochlea onwards - AC>BC - both decreased

Romberg test

fluid in semiCC still moving eyes catch up