Eye structure & function

Question 1

globe-shaped organ that consists of three

layers

Answer 1

eyeball

Question 2

white, outermost layer that provides strength, structure, and shape to the eye

Answer 2

sclera

Question 3

thin mucous membrane covering the
outer surface of the eye that contains blood
vessels and secretory glands

Answer 3

conjunctiva

Question 4

dark-blue middle layer that supplies blood to the entire eye

Answer 4

choroid

Question 5

attached to the retina; transmits

visual information to the brain

Answer 5

optic nerve

Question 6

transparent bulge of the sclera that allows

light into the eye

Answer 6

cornea

Question 7

surrounds the pupil and gives eyes their color

Answer 7

iris

Question 8

dilates to allow more light to enter the eye; constricts to decrease the amount of light entering the eye

Answer 8

pupil

Question 9

attached to the lens; includes several

ciliary muscles

Answer 9

ciliary body

Question 10

cause the lens to change shape

when they contract or expand

Answer 10

ciliary muscles

Question 11

clear, firm, transparent disc in the middle
layer that can change shape to allow vision at
different distances

Answer 11

lens

Question 12

attach the ciliary body and

muscles to the lens

Answer 12

suspensory ligaments

Question 13

the process of rounding and

flattening of the lens that enables focus in both near and far vision

Answer 13

accommodation

Question 14

innermost layer of the eye containing two

types of visual receptors

Answer 14

retina

Question 15

visual receptors in the retina that function

in dim lighting to produce images in black and white

Answer 15

Rods

Question 16

visual receptors in the retina that detect

color and function in more brightly lit situations

Answer 16

cones

Question 17

fluid in the anterior chamber that

provides nourishment for the lens and cornea and bends light rays to focus them sharply onto the retina

Answer 17

aqueous humor

Question 18

small opening for drainage of aqueous humor

Answer 18

Schlemm’s canal

Question 19

jellylike substance in the posterior chamber that gives shape to the eye and bends light rays to focus them sharply onto the retina

Answer 19

vitreous humor

Question 20

produce tears that flow over the

eye’s surface

Answer 20

Lacrimal glands

Question 21

fluid to bathe, moisten, and lubricate the eye; serve a protective role by killing bacteria and washing away foreign debris

Answer 21

tears