7:7 Special Senses Key Terms

refracts

(bens) light rays so the rays focus on the retina.

vestibule

acts as the entrance to the two other parts of the inner ear

lens

circular structure located behind the pupil and suspended in position by ligaments.

cornea

circular, transparent part of the front of the sclera; it allows light rays to enter the eye.

aqueous humor

clear, watery fluid that fills the space between the cornea and iris

iris

colored portion of the eye

semicircular canals

contain a liquid and delicate, hairlike cells that bend when the liquid moves with head and body movements

pinna

elastic cartilage covered by skin.

choroid coat

interlaced with many blood vessels that nourish the eyes

viteous humor

jellylike substance that fills the area behind the lens.

retina

made of many layers of nerve cells which transmit the light impulses to the optic nerve

conmjunctiva

mucous membrane, lines the eyelids and covers the front of the eye to provide additioinal protection and lubrication.

sclera

outter most layer is the tough connective tissue

lacrimal glands

produce tears, which constantly moisten and cleanse the eye.

organ of Corti

receptor of sound waves

cochlea

shaped like a snail's shell, contains delicate, hairlike cells

tympanic membrane

sound waves travel through the auditory canal until they reach the eardrum.

eustachian tube

the middle ear is connected to the pharynx, or throat, by a tube.

pupil

the opening in the center of the iris

ossicles

three small bones in the middle ear that amplify sound waves

auditory canal

tube or canal