Ear Anatomy and Function

Vocabulary flashcards covering the anatomy and function of the ear, including the outer, middle, and inner ear, as well as equilibrium.

Outer Ear

The outermost part of the ear.

Pinna

Part of the outer ear; its function is to collect and direct sound waves into the ear.

External auditory meatus (canal)

Part of the outer ear; a canal that leads to the eardrum.

Ceruminous glands

Glands located in the external auditory meatus that secrete cerumen.

Tympanic membrane

The eardrum; a membrane that vibrates in response to sound waves.

Eardrum

Another name for the eardrum.

Auricle

Also known as the pinna.

Helix

The rim of the auricle.

Lobule

The earlobe.

Middle (internal) ear

Middle ear.

Inner ear

Inner ear.

Pharyngotympanic (auditory) tube

The auditory tube that connects the middle ear to the pharynx.

Auditory tube

A tube that connects the middle ear to the pharynx and equalizes air pressure on both sides of the eardrum.

Ossicles

Small bones in the middle ear that transmit sound vibrations.

Malleus

The first ossicle; Also known as the hammer.

Incus

The second ossicle; Also known as the anvil.

Stapes

The third ossicle. Also known as the stirrup.

Oval window

A membrane-covered opening that leads from the middle ear to the inner ear.

Round window

A membrane-covered opening in the middle ear wall that receives sound vibrations.

Tympanic cavity

Air-filled cavity in the temporal bone that houses the ossicles.

Tensor tympani muscle

A muscle in the middle ear that tenses the tympanic membrane in response to loud noises.

Stapedius muscle

A muscle in the middle ear that reduces the mobility of the stapes in response to loud noises.

Epitympanic recess

Space in the middle ear superior to the tympanic membrane.

Osseous labyrinth

The bony labyrinth filled with perilymph.

Membranous labyrinth

The membranous labyrinth filled with endolymph.

Perilymph

Fluid similar to cerebrospinal fluid, found between the bony and membranous labyrinths.

Endolymph

Fluid similar to intracellular fluid, found within the membranous labyrinth.

Vestibular apparatus

Part of the inner ear involved in balance.

Cochlea

Part of the inner ear involved in hearing.

Utricle and Saccule

Structures within the vestibule of the inner ear involved in static equilibrium.

Macula

Sensory receptor for static equilibrium located in the utricle and saccule.

Otolith

Small, dense stones made of calcium carbonate that are part of the macula.

Static equilibrium

The perception of head orientation; perceived by the macula.

Dynamic equilibrium

The perception of motion or acceleration; perceived by the macula or crista.

Linear Acceleration

The perception of moving forward or backward.

Linear Deceleration

The perception of slowing down.

Head Position

Relative position of the head.

Saccule and Utricle

Chambers containing the macula.

Otolithic membrane

A gelatinous structure in the macula that contains hair cells and otoliths.

Semicircular canals

The part of the inner ear consisting of semicircular ducts.

Semicircular ducts

The membranous labyrinth within the semicircular canals.

Ampulla

A widened part of the semicircular ducts that contains the crista.

Crista

Receptor for dynamic equilibrium located within the ampulla of the semicircular canals.

Cupula

A gelatinous mass that covers the hair cells of the crista ampullaris.

Rotational acceleration

Turning motion or acceleration.

Rotational deceleration

Slowing or stopping of turning motion.

Macula Utricle

The receptor for linear acceleration.

Macula Saccule

The receptor for linear acceleration.

Stereocilia

Fine hair-like projections on the hair cells within the macula.

Utricular macula

Stereocilia (microvilli) imbedded in otolithic membrane

Kinocilium

The largest stereocilia in saccule

Cochlea

A spiral-shaped structure in the inner ear that contains the organ of Corti.

Scala tympani and Scala vestibuli

Two fluid-filled ducts within the cochlea.

Spiral Organ = Organ of Corti

The sensory receptor for hearing, located within the cochlea.

Basilar membrane

A membrane in the cochlea that supports the organ of Corti.

Tectorial membrane

A membrane in the cochlea to which the stereocilia of the hair cells attach.

Scala media

Also known as the cochlear duct.

Vestibular Membrane

The membrane above the organ of Corti.

Audible vibration of molecules

A vibration of molecules that are audible.

Tympanic reflex

Protection of cochlea in response to loud, prolonged noises

Cranial Nerve VIII, Vestibulocochlear Nerve

Nerve VIII; Carries the signals for hearing and balance from the inner ear to the brain.

Pitch

The perceived frequency of sound vibrations.

Loudness

Perceived intensity of sound energy.

Localization of sound

Determines how and when we perceive sound.

Dynamic whole body equilibrium

Equilibrium that encompasses the entire body.