Hearing - Anatomy and Physiology Flashcards
(16 cards)
Organ of corti
Changes vibrations into nerve impulses which are picked up by the auditory nerve and sent to the temporal lobes.
Cochlea
Fluid filled structure housing the organ of corgi
Semi-Circular Canals
Fluid filled bony loops essential for balance
Inner Ear
Consists of bony, membranous structures surrounded by fluid
Contains semi-circular canals, oval window, cochlea and organ of corti
Ossicles
Bones in middle ear which transmit vibrations from tympanic membrane to inner ear.
Malleus, incus, stapes
Middle ear
Separated from the outer ear by the tympanic membrane.
Contains ossicles and Eustachian tube
Outer ear
Pinna
Collects sound waves and directs them to the external acoustic meatus
Oval window
Set into a fluid filled chamber in the inner ear
Eustachian tube
Opens into the pharynx and allows air pressure to equalise between the ear and outside air
Process of hearing stage 1
Sound waves hit the tympanic membrane
Process of hearing stage 2
These pressure waves pass from the tympanic membrane, through the external acoustic meatus to the middle ear, causing vibrations along the chain of ossicles from malleus to incus to stapes.
Process of hearing stage 3
The base of the stapes causes pressure to be exerted on the oval window
Process of hearing stage 4
The vibrations of the oval window change into waves of fluid pressure rippling through the cochlea
Process of hearing stage 5
The vibrations distort the hairs embedded in the organ of corti, causing them to produce nerve signals
Process of hearing stage 6
These signals pass along the cochlear nerve (which becomes part of the acoustic nerve) to the brain’s auditory cortex in the temporal lobe.
Process of hearing stage 7
Nerve impulses analysed to gauge frequency and intensity of original air pressure waves
