Chapter 17 The Eye

Question 1

accommodation

Answer 1

normal adjustment of the eye to focus on objects from far to near
ciliary body adjusts the lens, rounding it, and the pupil constricts
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
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 sclera

Question 6

ciliary body

Answer 6

structure surrounding the lens that connects the iris to the choroid
contains ciliary muscles that control the shape of the lens and secretes aqueous humor

Question 7

cone

Answer 7

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

Question 8

conjunctiva

Answer 8

delicate membrane lining the eyelids and covering the eyeball up to the cornea

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 of clearest vision

Question 11

fundus of the eye

Answer 11

posterior, inner part of the eye; visualized with an opthalmoscope

Question 12

iris

Answer 12

pigmented layer that opens and closes to allow more or less light into the eye; central opening is the pupil

Question 13

lens

Answer 13

transparent, biconvex body behind the pupil of the eye
bends light to bring them into focus on the retina

Question 14

macula

Answer 14

small oval regions of the retina near 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; 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; 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 low light and for peripheral vision

Question 22

sclera

Answer 22

tough, white outer coat of the eyeball