149 & 150 Special Sense: Vision

Question 1

most of the refraction of light takes place in the

Answer 1

cornea

Question 2

how is the aqueous humor formed

Answer 2

ciliary body secretes Na, which then pulls in water and Cl, other nutrients enter ia facilitated diffusion

Question 3

what is the flow of aqueous humor

Answer 3

flows through pupil, angle of anterior chamber, Trabecular meshwork, canal of schlemm, aqeuous ceins

Question 4

increased intraocular pressure leads to

Answer 4

glaucoma

Question 5

if you hace a closed angle, when will you hae symptoms

Answer 5

in the dark, when the eyes try to dialate

Question 6

what allows you to accomodate for far target

Answer 6

ciliary muscles relax, suspensory ligament contract

Question 7

what muscle helps with ocular conergence

Answer 7

medial rectus

Question 8

what is presbyopia

Answer 8

loss of accomodation of lens (seen with age)

Question 9

what is cycloplegia

Answer 9

loss of accomodation due to loss of ciliary muscle (atropine)

Question 10

Constriction _____ the angle of the anterior chamber

Answer 10

increases

Question 11

what is the pathway for pupillary reflex

Answer 11

light, CN II, pretectal area, EDINGER_WESTPHAL NUCLEUS, CN III, ciliary ganglion, ciliary muscles, constrictor pupilae

Question 12

what three things are in depth perception

Answer 12

size of object, moing parallax, steropsis

Question 13

where is itamin A stored

Answer 13

pigmented layer

Question 14

what is the light sensitie pigement in rods

Answer 14

rhodopsin

Question 15

what is rhodopsin composed of

Answer 15

scotopsin and retinal

Question 16

the unstimulated retinal is in _____ form

Answer 16

cis

Question 17

what happens when retinal is conerted to all trans

Answer 17

no longer fits with scotopsin -> bathorrhodopsin -> decays into lumirhodospin-> metarhodopsin

Question 18

what conerts all trans retinal to cis

Answer 18

isomerase

Question 19

unstimulated rods are _______

Answer 19

depolarized (Na influx through cGMP gated channels)

Question 20

upon stimulation with light, rods become

Answer 20

hyperpolarized

Question 21

destabilization of rhodopsin actiates

Answer 21

transducin

Question 22

what does transducin actiate

Answer 22

cGMP phosphodiesterase

Question 23

how can viagra cause blindness

Answer 23

it inhibits phospodiesterase, resulting in the cells staying depolarized and not reacting to light

Question 24

what inactates metarhodopsin II

Answer 24

rhodopsin kinase

Question 25

Rods dont see

Answer 25

Red

Question 26

when is pigment converted to vitamin A

Answer 26

bright light

Question 27

what role does calcium play in light adaptation

Answer 27

indirectly regualtes cGMP dependent channels

Question 28

which cells sharpen retinal image

Answer 28

biolar

Question 29

which cells provide contrast

Answer 29

horizontal

Question 30

which cells control light senstitivity

Answer 30

amacrine

Question 31

the output of horizontal cells is always

Answer 31

inhibitory

Question 32

which cells are responsible for circadia rhythm

Answer 32

ganglion cells

Question 33

are p or m cells sensitive to color

Answer 33

P (less sensitive overall and does fine details)

Question 34

what nucleus of hypothalamus controls circadian rhytm

Answer 34

suprachiasmatic nucleus

Question 35

what area of the thalamus does reflex movement of the eye

Answer 35

pretectal

Question 36

what area of the brain does rapid directional movement of both eyes

Answer 36

superior colliculi

Question 37

lateral geniculate nuclei sends fibers to

Answer 37

EW