Special Senses Review Quizlet

tinnitus

ringing in the ears

vertigo

the sensation of dizziness

audiometer

instrument to measure hearing

audiogram

record of hearing (results from an audiometer)

auricle/pinna

external portion of the ear

auditory canal

the area that sound waves pass through to reach the eardrum

tympanic membrane

The eardrum. A structure that separates the outer ear from the middle ear and vibrates in response to sound waves.

ossicles

malleus, incus, stapes (bones of the middle ear)

Eustachian tube

A narrow tube between the middle ear and the throat that serves to equalize pressure & provide drainage

oval window

the membrane that separates the middle ear from the inner ear

semicirular canals

Three tiny tubes in the inner ear, filled with fluid to assist in balance.

vestibule of ear

the area between cochlea & semicircular canals that assists with acceleration and gravity

labryinth

a network of winding passages; maze-like inner ear

mastoid cells

hollow air spaces located in the mastoid process of the temporal bone

Cilliated cells

located in the inner ear and trasmit messages of sound and equilibrium to the auditory nerve

Organ of Corti

Center part of the cochlea, containing hair cells, canals, and membranes - true organ of hearing

cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

vestibulcochlear nerve

auditory nerve transmitting information of hearing and balance

endolymph and perilymph

fluids in the labyrinth of the inner ear help with transmission of sound waves

cerumen

a waxy substance secreted by glands located throughout the external canal

Cornea

the transparent, avascular window to the eye

aqueous humor

fluid in the eye, found between the cornea and the lens

Canal of Schlemm

Drains the aqueous humor of the eye

Iris

circular muscle that forms the colored portion of the eye and controls the size of the pupil opening

pupil

the opening in the center of the eye through which light enters

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

suspensory ligaments

Hold the lens in place and connects it to the ciliary muscles

cilary body

A ring of muscles that controls the shape of the lens to allow the eye to focus

vitrious humor

clear gel-like liquid that fills space between lens and retina, gives eyeball shape, maintains pressure

Retina

Light sensitive layer of the eye; contains rods and cones

choroid

middle, vascular layer of the eye, between the retina and the sclera

sclera

white of the eye, outer tunic or layer of the eye

optic nerve

carries neural impulses from the eye to the brain

Rods

retinal receptors that detect black, white, and gray; necessary for peripheral and night vision

Cones

retinal receptor cells that function in daylight and detect fine detail and color vision.

fovea centralis

tiny pit or depression in the retina that is the region of clearest vision

Vitamin A deficiency

night blindness

conjunctiva

mucous membrane that lines the eyelids and outer surface of the eyeball

blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there

lacrimal apparatus

produces, distributes, and removes tears

snellen chart

used to measure visual acuity

ophthalmoscope

instrument used to examine the interior of the eye

accommodation

lens changes shape to focus near or far objects on the retina

Homeostasis

process by which organisms maintain a relatively stable internal environment

Bedsted

name that origninates from Denmark