Eye Structures

Question 1

Eyelash

Answer 1

protect eyes by initiating blinking when touched and keeping out dust

Question 1

Eyebrow

Answer 1

shade the eye; keep dust and perspiration out of the eyes

Question 2

Eyelids (palpebrae)

Answer 2

blinking protects the eyes from debris and bright light and spreads fluid over the eye that keeps the eye from drying out

Question 3

palpebral fissure

Answer 3

space between the eyelids that allows light to enter the eye when eyelids are open

Question 4

Medial and lateral commissures (canthii)

Answer 4

location where the upper and lower eyelids meet medially and laterally

Question 5

lacrimal caruncle

Answer 5

contains sebaceous and sweat glands

Question 6

tarsal (meibomian) glands

Answer 6

produce a lipid-rich secretion that prevents the eyelids from sticking together

Question 7

conjunctiva

Answer 7

a transparent protective membrane of stratified squamous epithelium; produces a lubricating mucus that prevents eyes from drying out

Question 8

Your co-pilot is cheering you on- true or false

Answer 8

true

Question 9

palpebral conjuctiva

Answer 9

lines the posterior surface of the eyelids

Question 10

ocular (bulbar) conjuctiva

Answer 10

lines the sclera (white of the eye) on the anterior surface of the eyeball

Question 11

Lacrimal glands

Answer 11

release a saline solution called lacrimal secretion (tears) that protects and moistens the eye; contains mucus, antibodies, and lysozymes

Question 12

extrinsic eye muscles

Answer 12

hold eyeball in eye socket, help maintain eyeball shape, and produce eye movement

Question 13

lens

Answer 13

focuses light on the retina of the eye

Question 14

fibrous tunic

Answer 14

outermost layer of dense connective tissue; protects the eyeball

Question 15

sclera

Answer 15

covers all but the anterior most part of the eyeball; is continuous with the dura mater of the brain

Question 16

cornea

Answer 16

transparent layer that covers the anterior-most sixth of the eyeball

Question 17

vascular tunic (uvea)

Answer 17

intermediate layer of the eyeball

Question 18

choroid

Answer 18

highly vascularized layer that lines posterior of eyeball; dark melanin pigments prevent light from being scattered

Question 19

ciliary body

Answer 19

smooth muscles that control lens shape; connected to lens by suspensory ligaments; also produces the aqueous humor

Question 20

iris

Answer 20

anterior most portion of uvea; composed of smooth muscles that regular the amount of light entering the eye through the pupil

Question 21

pigmented layer

Answer 21

lines the entire posterior cavity; prevents scattering of light and has cells that act as phagocytes and store vitamin A

Question 22

neural layer

Answer 22

layer on surface of posterior cavity that is actually responsible for vision; extends anteriorly to the ora serrata

Question 23

rods

Answer 23

photoreceptors that responds to dim light and are responsible for peripheral vision; do not see color

Question 24

cones

Answer 24

photoreceptors that respond to bright light and are responsible for high definition color vision

Question 25

macula lutea

Answer 25

area at posterior of eyeball containing a very high concentration of cones

Question 26

fovea centralis

Answer 26

area at center of macula lutea with the highest concentration of cones and the sharpest vision

Question 27

bipolar cells/ganglion cells

Answer 27

transmit visual signals toward the brain

Question 28

horizontal cells/amacrine cells

Answer 28

faciliate or inhibit communication between photoreceptors and ganglion cells to adjust contrast of image send to brain

Question 29

optic disc

Answer 29

blind spot that has no photoreceptors; location where the optic nerve (cranial nerve II) originates and where the blood supply enters the eye

Question 30

posterior cavity

Answer 30

area posterior to the lens; filled with clear vitreous humor

Question 31

vitreous humor

Answer 31

supports posterior surface of lens, and holds retina in place

Question 32

anterior cavity

Answer 32

area anterior to the lens; filled with clear aqueous humor; divided into a posterior and anterior chamber by the iris

Question 33

aqueous humor

Answer 33

creates the intraocular pressure of the eye; supplies nutrients to, and removes waste from the lens and cornea

Question 34

canal of Schlemm

Answer 34

drains excess aqueous humor from anterior cavity of eye