Biology 30 Human Ear

Front 1

Pinna

Back 1

Outer part of ear, funnels sound into the ear.

Front 2

Auditory Canal

Back 2

Carries sound waves to eardrum

Front 3

Tympanic membrane (eardrum)

Back 3

Thin layer of tissue that receives sound vibrations

Front 4

Ossicles

Back 4

Tiny bones that amplify and carry sound to the middle ear

Front 5

Eustachian tube

Back 5

Tube in middle ear that equalizes pressure

Front 6

Vestibule

Back 6

Chamber at the base of the semicircular canals that provides information about static equilibrium

Front 7

Semicircular canals

Back 7

Fluid filled structures in the inner that provides information about dynamic equilibrium

Front 8

Cochlea

Back 8

Coil structure of the inner ear that converts sound waves into nerve impulses. Contains hair cells.

Front 9

Utricle and saccule

Back 9

Part of the vestibule. They establish head position

Front 10

Oval window

Back 10

Oval shaped hole in vestibule covered by thin tissue

Front 11

Organ of corti

Back 11

Inside cochlea, covered with hair cells that respond to vibrations in basilar membrane (where hair cells are attached). Movement stimulates sensory nerves.

Front 12

Static equilibrium

Back 12

Cilia from hair cells suspended in gelatinous matter contains little rocks (otoliths). Gravity causes otoliths to move, gel to move, cilia to bend. Stimulates sensory nerve.

Front 13

Conductive hearing loss

Back 13

Sound waves can't enter inner ear. Hearing aids can be used.

Front 14

Sensorineaural hearing loss

Back 14

Auditory nerve is severed or damaged. Cochlear implants can be used.

Front 15

Dynamic equilibrium

Back 15

Semicircular canals have an ampulla which holds a cupulla. Rotating causes fluid inside to move which bends cilia on hair cells in cupulla to move. Nerve impulse.