Chapter 17 Eye and Ear
auditory meatus
Auditory canal
eustachian tube
Auditory tube
conjunctiva
Delicate membrane lining the eyelids and covering the anterior eyeball.
cornea
Fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball.
choroid
Middle, vascular layer of the eye, between the retina and the sclera.
accommodation
Normal adjustment of the eye to focus on objects from far to near.
optic disc
Region at the back of the eye where the optic nerve meets the retina.
ossicle
Small bone of the ear; include the malleus, incus, and stapes.
sclera
Tough, white outer coat of the eyeball
cerumen
Waxy substance secreted by the external ear (earwax).
anterior chamber
area behind the cornea and in front of the lens and iris.
refraction
bending of light rays by the cornea, lens, and fluids of the eye to bring the rays into focus on the retina
pupil
black circular opening in the center of the iris through which light passes as it enters the eye
auditory canal
channel that leads from the pinna to the eardrum
iris
colored pigmented membrane surrounding the pupil of the eye
malleus
first ossicle of the middle ear; malleus means hammer
auricle
flap of the ear; the protruding part of the external ear, or pinna
aqueous humor
fluid produced by the ciliary body and found in the anterior chamber.
labyrinth
maze like series of canals of the inner ear
typanic membrane
membrane between the outer and middle ear; eardrum
incus
second ossicle (bone) of the middle ear; incus means anvil
cochlea
snail-shaped, spirally wound tube in the inner ear; contains hearing-sensitive receptor cells
vitreous humor
soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball
retina
the light sensitive nerve cell layer of the eye, containing photoreceptor cells
stapes
third ossicle of inner ear, stapes means stirrup
macula
yellowish region on the retina lateral to and slightly below the optic disc; contains the fovea centralis, which is the area of clearest vision
