Special Senses

Question 1

ciliary body

Answer 1

anterior portion

smooth muscle, changes shape of the lens

Question 2

iris

Answer 2

colored part of the eye, contracts and relaxes

continuous with the ciliary body

Question 3

choroid

Answer 3

helps focus light and keep it from bouncing around
contains brown pigment
highly vascularized

Question 4

retina

Answer 4

pigmented layer, epithelial cells, absorbs xs light
neural layer, contains the photoreceptors
bipolar cells and ganglion cells (these are neurons)

Question 5

optic disc

Answer 5

where optic nerve exits the eyeball
no photoreceptors here
blind spot

Question 6

macula lutae

Answer 6

oval region of the eye
contains mostly cones
important fro high visual acuity - a sharp image
in the center is a small pit

Question 7

fovea centralis

Answer 7

only cones in the center of the macula lutea
as you move away from FC, fewer and fewer cones
only the size of a pinhead, why we constantly move our eyeballs to see

Question 8

posterior segment

Answer 8

filled with vitreous humor, a watery gel, reacts to introcular pressure, keeps eyeball round and no collapsing
VH forms during embryo, what we have at birth stays with us for life

Question 9

anterior segment

Answer 9

cornea_> lens
aqueous humor, provides nutrients and O2 to this region
unlike VH, constantly replaced
brings new O2 to cornea and lens and helps remove waste products

Question 10

rhodopsin

Answer 10

pigment of the rods
retinal - a light absorbing molecule
derived from vitamin A

Question 11

photopsin

Answer 11

also has retinal, in the cones

Question 12

colors of cones

Answer 12

blue red and green

Question 13

emmetropic

Answer 13

normal

Question 14

myopic eye

Answer 14

too long, nearsightedness

Question 15

hyperopia

Answer 15

too short eyeball, farsightedness

Question 16

astigmatism

Answer 16

unequal curvature of the cornea or lens