physiology-ear Flashcards
what dictates the pitch of a sound?
frequency
what dictates the intensity of a sound?
amplitude
what frequency can humans hear?
20Hz-20,000Hz
what graph can be used to cover hearing range?
audiogram
what do the ‘O’ and ‘X’ represent in an audiogram?
o= right ear air conduction
x=left ear air conduction
what allows amplification of sound in the middle ear?
-size of tympanic membrane compared to oval window (18:1)
what are the three parts inside the cochlear?
- scala tympani (contains perilymph)
- cochlear duct/ scala media (contains endolymph)
- scala vestibuli (contains perilymph)
where are the inner hair cells found in the cochlea?
-in the organ of corti
what is the role of the inner hair cells?
-involved in receiving sound and passing the sound up the auditory nerve by turning it into action potential (they sway causing voltage gates to open, causing depolarisation, creating an action potential)
what is the role of the outer cells?
-modifying sound
where is the primary auditory complex located?
left posterior superior tempoal gyrus (Broadmans area 41/42)
what is the role of the eustachian tube?
equalise pressure in ears
what is the resting state of the eustachian tube like?
-it is closed but can be opened by tensor veli palatini and levator palatine muscles
what role does have external ear have in hearing?
sound collector
what role does the middle ear have in hearing?
mechanical force of amplification