Special Senses: Hearing and Balance

Structures composing the outer ear

Auricle (pinna), External acoustic meatus (auditory canal), and Tympanic membrane (eardrum)

Structures composing the boney or osseous labyrinth

Cochlea, vestibule, and semicircular canals

Collectively called ossicles

Hammer (malleus), Anvil (incus), and Stirrup (stapes)

Ear structures not involved with hearing

Vestibule and Semicircular canals

Allows pressure in the middle ear to be equalized with the atmospheric pressure

Pharyngotympanic (auditory) tube

Vibrates as sound waves hit it, transmits the vibrations to the ossicles

Tympanic membrane (eardrum)

Contains the organ of Corti

Cochlea

Connects the nasopharynx and the middle ear

Pharyngotympanic (auditory) tube

Contain receptors for the sense of equilibrium

Vestibule and semicircular canals

Transmits the vibrations from the stirrup to the fluid in the inner ear

Oval window

Fluid that bathes the sensory receptors of the inner ear

Endolymph

Fluid contained within the osseous labyrinth, which bathes the membranous labyrinth

Perilympth

The receptors for the ___ equilibrium are found in the crista ampullaris of the ___.

Dynamic and Semicircular canals

These receptors (dynamic) respond to changes in ___ motion.

Angular/rotatory

When motion begins, the ___ fluid lags behind the ___ is bent, which excited the hair cells.

Endolymph, cupula

The receptors for ___ equilibrium are found in the maculae of the ___ and ___.

Static, saccule, and utricle

Tiny stones found in a gel overlying the hair cells and roll in response to the pull of ___.

Gravity

Besides the equilibrium receptors of the inner ear, the senses of ___ and ___ are also important in helping to maintain equilibrium.

Proprioception and vision

Can result from the fusion of the ossicles

Condition relating to conduction deafness

Can result from damage to the cochlear nerve

Condition relating to sensorineural (central) deafness

Sound is heard in one ear but not in the other during both bone and ir conduction

Condition relating to sensorineural (central) deafness

Often improved by a hearing aid

Condition relating to conduction deafness

Can result from otitis media

Condition resulting from conduction deafness

Can result from excessive earwax or perforated eardrum

Condition resulting from conduction deafness

Can result from a blood clot in the auditory cortex of the brain

Condition resulting from sensorineural (central) deafness

Eardrum → ___ → ___ → ___ → oval window → ___ → ___ → ___ → hair cells

hammer (malleus), anvil (incus), stirrup (stapes)

perilymph, ____ membrane, endolymph