Sense Organs Vocab

Question 1

accommodation

Answer 1

normal adjustment of the eye to focus on objects from far to near. The ciliary body adjusts the lens (rounding it) and the pupil constricts. When the eye focuses from near to far, the ciliary body flattens the lens and the pupil dilates

Question 2

anterior chamber

Answer 2

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

Question 3

aqueous humor

Answer 3

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

Question 4

biconvex

Answer 4

consisting of two surfaces that are rounded, elevated, and curved evenly, like part of a sphere. The lens of the eye is a biconvex body

Question 5

choroid

Answer 5

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

Question 6

ciliary body

Answer 6

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

Question 7

cone

Answer 7

photoreceptor cell in the retina that transforms light energy into a nerve impulse. Cones are responsible for color and central vision

Question 8

conjunctiva

Answer 8

delicate membrane lining the undersurface of the eyelids and covering the anterior eyeball

Question 9

cornea

Answer 9

fibrous transparent layer of clear tissue that extends over the anterior portion of the eyeball.

Question 10

fovea centralis

Answer 10

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

Question 11

fundus of the eye

Answer 11

posterior, inner part of the eye

Question 12

iris

Answer 12

pigmented layer that opens and closes to allow more or less light into the eye. The central opening of the iris is the pupil

Question 13

lens

Answer 13

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

Question 14

macula

Answer 14

yellowish region on the retina lateral to and slightly below the optic disc; contains the fovea centralis, which is the area of clearest vision

Question 15

optic chiasm

Answer 15

point at which optic nerve fibers cross in the brain

Question 16

optic disc

Answer 16

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, and is thus insensitive to light

Question 17

optic nerve

Answer 17

cranial nerve carrying impulses from the retina to the brain (cerebral cortex)

Question 18

pupil

Answer 18

central opening of the eye, surrounded by the iris, through which light rays pass. It appears dark

Question 19

refraction

Answer 19

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

Question 20

retina

Answer 20

light sensitive nerve cell layer of the eye containing photoreceptor cells (rods and cones)

Question 21

rod

Answer 21

photoreceptor cell of the retina essential for vision in dim light and for peripheral vision

Question 22

sclera

Answer 22

tough, white outer coat of the eyeball

Question 23

thalamus

Answer 23

relay center of the brain. Optic nerve fibers pass through the thalamus on their way to the cerebral cortex

Question 24

vitreous humor

Answer 24

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

Question 25

auditory canal

Answer 25

channel that leads from the pinna to the eardrum

Question 26

auditory meatus

Answer 26

auditory canal

Question 27

auditory nerve fibers

Answer 27

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

Question 28

auditory tube

Answer 28

channel between the middle ear and the nasopharynx; Eustachian tube

Question 29

auricle

Answer 29

flap of the ear; the protruding part of the external ear; pinna

Question 30

cerumen

Answer 30

waxy substance secreted by the external ear; earwax

Question 31

cochlea

Answer 31

snail-shaped, spirally wound tube in the inner ear; contains hearing-sensitive receptor cells

Question 32

endolymph

Answer 32

fluid within the labyrinth of the inner ear

Question 33

Eustachian tube

Answer 33

auditory tube

Question 34

incus

Answer 34

second ossicle (bone) of the middle ear; incus means anvil

Question 35

labyrinth

Answer 35

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

Question 36

malleus

Answer 36

first ossicle of the middle ear; means hammer

Question 37

organ of Corti

Answer 37

sensitive auditory receptor area found in the cochlea of the inner ear

Question 38

ossicle

Answer 38

small bone of the ear; includes the malleus, incus, and stapes

Question 39

oval window

Answer 39

membrane between the middle ear and the inner ear

Question 40

perilymph

Answer 40

fluid contained in the labyrinth of the inner ear

Question 41

pinna

Answer 41

auricle; flap of the ear

Question 42

semicircular canals

Answer 42

passages in the inner ear associated with maintaining equilibrium

Question 43

stapes

Answer 43

third ossicle of the middle ear. means stirrup

Question 44

tympanic membrane

Answer 44

membrane between the outer and the middle ear; also called the eardrum

Question 45

vestibule

Answer 45

central cavity of the labyrinth, connecting the semicircular canals and the cochlea. The vestibule contains two structures, the saccule and utricle, that help maintain equilibrium