Page 948 - Atlas of Histology with Functional Correlations

SECTION 2 • Auditory System

Ear is specialized for hearing, balance, and maintenance of equilibrium

EXTERNAL EAR

Auricle, or pinna, gathers sound waves and directs them through external
auditory canal
Sound waves reach eardrum or tympanic membrane

MIDDLE EAR

Contains a small, air-filled cavity called tympanic cavity in temporal bone of
the skull

Tympanic membrane separates external auditory canal from middle ear
Contains three very small bones, the auditory ossicles: stapes, incus, and
malleus
Contains auditory (eustachian) tube that communicates with nasopharynx

Auditory tube equalizes air pressure on both sides of tympanic membrane

INNER EAR

Lies deep in the temporal bone of the skull
Consists of semicircular canals, vestibule, and cochlea, which is called bony
labyrinth

In bony labyrinth is the membranous labyrinth, a series of compartments
filled with fluid
All sections of bony labyrinth filled with fluid perilymph
Membranous labyrinth filled with fluid endolymph

Cochlea

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