Ear

Pinna (auricle)

The outer ear structure that collects and funnels sound waves into the ear canal.

Eardrum (tympanic membrane)

A thin membrane that vibrates when sound waves hit it, crucial for transmitting sound to the middle ear.

Ossicles

Three tiny bones in the middle ear (malleus, incus, stapes) that amplify vibrations from the eardrum to the inner ear.

Oval window

The membrane that the stapes presses against, leading to fluid movement in the cochlea.

Cochlea

A fluid-filled, spiral-shaped organ in the inner ear that converts sound vibrations into nerve signals.

Basilar membrane

A membrane in the cochlea that moves in response to fluid waves and has organ of Corti, which contains hair cells.

Hair cells

Sensory receptors in the cochlea that convert mechanical movement into electrical signals.

Stereocilia

Tiny projections on hair cells that bend and open ion channels when the basilar membrane moves.

Tonotopic organization

The arrangement in the cochlea where different frequencies are processed at different locations along the basilar membrane.

Inner hair cells

Primary sensory receptors for hearing that transmit auditory information to the brain.

Outer hair cells

Hair cells that amplify and fine-tune sound by changing length in response to stimulation.

Cochlear amplifier

The function of outer hair cells that enhances movement of the basilar membrane for better sound detection.

Auditory nerve (cranial nerve VIII)

The nerve that carries auditory information from the hair cells to the brain.

Auditory cortex

The part of the brain that processes sound information and constructs the perception of sound.

Vestibular system

The part of the inner ear that helps detect head movement and maintain balance.

Semicircular canals

Structures in the vestibular system that detect rotational movement.

Utricle

A structure in the inner ear that detects horizontal linear acceleration and head position.

Saccule

A structure in the inner ear that detects vertical linear acceleration and head position.