Functions of the Ear

Ossicles

The three tiniest bones in the body form the coupling between the vibration of the eardrum and the forces exerted on the oval window of the inner ear.

Vestibule

The two membranous sacs of the vestibule, the utricle and the saccule, are known as the otolith organs. Because they respond to gravitational forces, they are also called gravity receptors.

Cochlea

a spiral-shaped, fluid-filled inner ear structure; it is lined with cilia (tiny hairs) that move when vibrated and cause a nerve impulse to form.

Tympanic Membrane

a thin membrane that vibrates when sound waves reach it.

Malleus (Hammer)

a tiny bone that passes vibrations from the eardrum to the anvil.

Incus (Anvil)

a tiny bone that passes vibrations from the hammer to the stirrup.

Stapes (Stirrup)

a tiny, U-shaped bone that passes vibrations from the stirrup to the cochlea. This is the smallest bone in the human body (it is 0.25 to 0.33 cm long).

Eustachian Tube

a tube that connects the middle ear to the back of the nose; it equalizes the pressure between the middle ear and the air outside. When you "pop" your ears as you change altitude (going up a mountain or in an airplane), you are equalizing the air pressure in your middle ear.

Round Window

allow for pressure changes between the middle ear and the cochlea.

External Auditory Canal

allows efficient sound transmission from the environment to the tympanic membrane.

Oval Window

an oval opening at the head of the cochlea, connecting the middle and inner ear, through which sound vibrations of the stapes are transmitted.

Vestibular Nerve

responsible for both hearing and balance and brings information from the inner ear to the brain. A human's sense of equilibrium is determined by this nerve.

Cochlear Nerve (Auditory Nerve)

sensory nerve that transfers auditory information from the cochlea (auditory area of the inner ear) to the brain. It is one of the many pieces that make up the auditory system, which enables effective hearing.

Sensory Hair Cell

sensory receptors in the inner ear that detect sound and head motion to begin the processes of hearing and balance control.

Pinna (Auricles)

the visible part of the outer ear. It collects sound and directs it into the outer ear canal

Semicircular Canals (Vestibular Apparatus)

three loops of fluid-filled tubes that are attached to the cochlea in the inner ear. They help us maintain our sense of balance.