Chapter 17: Sense Organs - Eyes and Ears

anterior chamber

Area behind the cornea and in front of the lens and iris. It contains aqueous humor

aqueous humor

Fluid produced by the ciliary body and found in the anterior chamber.

biconvex

Consisting of two surfaces that are rounded, elevated, and curved evenly, like part of a sphere

ciliary body

Structure surrounding the lens that connects the iris to the choriod. It contains ciliary muscles, which control the shape of the lens, and it secretes aqueous humor

cone

Photoreceptor cell in the retina that transforms light energy into a nerve impulse. Responsible for color and central vision

fovea centralis

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

fundus of the eye

Posterior, inner part of the eye; visualized with an ophthalmoscope

lens

Transparent, biconvex body behind the pupil of the eye. It bends (refracts) light rays to bring them into focus on the retina.

macula

Small oval region on the retina near the optic disc; contains the fovea centralis, which is the area clearest vision.

optic chiasm

Point at which optic nerve fibers cross in the brain

optic disc

Region at the back of the eye where the optic nerve meets the retina. It is the blind spot of the eye because it contains only nerve fibers, no rods or cones. This makes it insensitive to light

refraction

Bending of light rays by the cornea, lens, and fluids of the eye to bring the rays into focus on the retina.

vitreous humor

Soft, jelly-like material behind the lens in the vitreous chamber; helps maintain the shape of the eyeball

conjunctiv/o

conjunctiva

blephar/o

eyelid

cor/o

pupil

cycl/o

ciliary body or muscle of the eye

dacry/o

tears, tear duct

ir/o, irid/o

iris

kerat/o, corne/o

cornea (2)

palpebr/o

eyelid

papill/o

optic disc; nipple-like

phac/o, phak/o

lens of the eye

uve/o

uvea

uvea

vascular layer of the eye; 3 parts - choroid, iris, cilliary body

vitre/o

glassy

ambyl/o

dull, dim

dipl/o

double

glauc/o

gray

mi/o

smaller, less

mydr/o

widen, enlarge

nyct/o

night

phot/o

light

presby/o

old age

scot/o

darkness

xer/o

dry

-opia, -opsia

vision (suffixes)

-tropia

to turn

auditory canal, auditory meatus

Channel that leads from the pinna to the eardrum.

auditory meatus

Auditory canal

auditory nerve fibers

Carry impulses from the inner ear to the brain (cerebral cortex). These fibers compose the vestibulocochlear nerve (cranial nerve VIII).

auditory tube

Channel between the middle ear and the nasopharynx

eustachian tube.

auditory tube

auricle

The protruding part of the external ear, or pinna.

cerumen

Waxy substance secreted by the external ear; earwax.

cochlea

Snail shell–shaped, spirally wound tube in the inner ear; contains hearing-sensitive receptor cells.

endolymph, perilymph

Fluid within the labyrinth of the inner ear.

labyrinth

Maze-like series of canals of the inner ear. This includes the cochlea, vestibule, and semicircular canals.

organ of Corti

Sensitive auditory receptor area found in the cochlea of the inner ear.

ossicle

Small bone of the ear; includes the malleus, incus, and stapes.

oval window

Membrane between the middle ear and the inner ear.

semicircular canals

Passages in the inner ear associated with maintaining equilibrium.

tympanic membrane

Membrane between the outer and the middle ear; also called the eardrum.

vestibule

Central cavity of the labyrinth, connecting the semicircular canals and the cochlea. Contains two structures, the saccule and utricle, that help to maintain equilibrium.

saccule

one of two structures that make up the vestibule

utricle

one of two structures that make up the vestibule

acous/o, audi/o

hearing

audit/o

hearing (root)

aur/o, auricul/o

ear

cochle/o

cochlea

ossicul/o

ossicle (combining form)

ot/o

ear

salping/o

eustachian tube, auditory tube

staped/o

stapes (third ear of middle ear)

myring/o, tympan/o

eardrum, tympanic membrane

vestibul/o

Vestibule

-acusis, -cusis

hearing (suffixes)

-otia

ear condition