Organs & Atomic structures

Flashcards for key vocabulary related to the anatomy of the ear, covering the external, middle, and inner ear.

Ear

Organ of hearing and balance; includes the external ear, middle ear, and inner ear.

External Ear

Consists of the auricle and external auditory canal (meatus).

Auricle

External, visible part of the ear located on both sides of the head; directs sound waves into the external auditory canal (also called pinna).

External Auditory Canal

Short tube that ends at the tympanic membrane. The inner part lies within the temporal bone of the skull and contains the glands that secrete earwax (cerumen). (also called external auditory meatus)

Middle Ear

Consists of the tympanic membrane and the tympanic cavity containing the ossicles.

Tympanic Membrane

Semitransparent membrane that separates the external auditory canal and the middle ear cavity. The tympanic membrane transmits sound vibrations to the ossicles. (also called eardrum)

Ossicles

Bones of the middle ear that carry sound vibrations. The ossicles are composed of the malleus (hammer), incus (anvil), and stapes (stirrup). The stapes connects to the oval window, which transmits the sound vibrations to the cochlea of the inner ear.

Eustachian Tube

Passage between the middle ear and the pharynx; equalizes air pressure on both sides of the tympanic membrane.

Inner Ear

Consists of the labyrinth and connectors of the vestibular and the cochlear nerves.

Labyrinth

Bony spaces within the temporal bone of the skull made up of three distinct parts, the cochlea, the semicircular canals, and the vestibule. The cochlea facilitates hearing. The semicircular canals and the vestibule facilitate equilibrium and balance.

Cochlea

Coiled portion of the inner ear containing the sensory organ for hearing, connects to the oval window in the middle ear.

Semicircular Canals and Vestibule

Sensory organs of balance; contain receptors and endolymph that provide sense information about the body's position to maintain equilibrium.

Vestibulocochlear Nerves

Paired cranial nerves responsible for hearing and balance; composed of vestibule fibers and cochlear fibers (also called acoustic nerve or auditory nerve).

Vestibular Nerve

Conveys information about position and balance from the semicircular canals and vestibule to the brain.

Cochlear Nerve

Conveys information about sound, including volume and frequency, from the cochlea to the brain.

Mastoid Bone

Portion of the temporal bone of the skull posterior and inferior to each auditory canal; contains mastoid air cells that drain into the middle ear cavity behind the external auditory canal (also called mastoid process).