Vision

Question 1

When the ciliary muscle in the eye is ___, the lens is an oval shape which allows you to see ____

Answer 1

relaxed; far away

Question 2

When the ciliary muscle in the eye is ____, the lens is a round shape which allows for

Answer 2

contracted; accomodation

Question 3

Myopic is

Answer 3

nearsighted

Question 4

Hyperopic is

Answer 4

farsighted

Question 5

In nearsighted patients, the eyeball is too ___ so faraway objects focus at a point ____ of the retina

Answer 5

long; in front

Question 6

In farsighted patients, the eyeball is too ___ so near objects focus ___ the retina

Answer 6

short; behind

Question 7

___ are the photoreceptors used in dark environments

Answer 7

rods

Question 8

Rods contain ___ and the gene is located on chromosome __

Answer 8

rhodopsin; 3

Question 9

___ are the photoreceptors used in bright environments

Answer 9

cones

Question 10

Cones contain ___ and the violet gene is located on chromosome __ while the green and yellow-green genes are located on chromosome __

Answer 10

photopsin/iodopsins; 7; X

Question 11

Trichromatic individuals have 3 color pigment types; violet is ___ wave, green is the ____ wave, and green-yellow is the ___ wave

Answer 11

S; M; L

Question 12

Each pigment contains both ___ and ___

Answer 12

opsin and retinol

Question 13

Retinal is a derivative of ____

Answer 13

Vitamin A

Question 14

Carotenoids are A ____

Answer 14

provitamins

Question 15

Retinal changes shape based on dark or light, and is in the ___ form in the dark and ___ form in the light

Answer 15

cis; trans

Question 16

In the dark, sodium moves __, and there is lots of cGMP in the cell attached to the Na+ channels

Answer 16

in

Question 17

In the light, sodium does not move in and the sodium channel is __; cGMP is broken down to GMP so that it detaches from the sodium channel

Answer 17

closed

Question 18

Off bipolar cells are ____ by glutamate

Answer 18

depolarized

Question 19

On bipolar cells are ____ by glutamate

Answer 19

hyperpolarized

Question 20

Off bipolar cells function to detect ___

Answer 20

dark

Question 21

On bipolar cells function to detect ___

Answer 21

light

Question 22

An off bipolar cell depolarizes when the photoreceptors that synapse with it are in the ____

Answer 22

dark

Question 23

An on bipolar cell depolarizes when the photoreceptors that synapse with it are in the ___

Answer 23

light

Question 24

What happens with ON bipolar cells when no light is absorbed?

Answer 24

1-Na+ and Ca++ into cell
2-Na+ depolarizes cell
3-Ca++ in causes glutamate to be released from synaptic terminal
4-The glutamate causes hyperpolarization of ON bipolar cell
5-Ca++ channels on bipolar cell close and no NT is released to the ganglion cell
6-no AP occur along axon of ganglion cell

Question 25

What happens with ON bipolar cells when light is absorbed?

Answer 25

1-Light comes in and is absorbed
2-light activates G protein, alpha subunit activates cGMP phosphodiesterase
3-cGMP is broken down into GMP and gated channels close
4-photoreceptor hyperpolarizes
5-no AP continues down presynaptic terminal; no glutamate is released
6-Absence of glutamate causes depolarization of ON bipolar cell
7-Ca++ channels open and glutamate is released
8-AP occurs along axon of ganglion cell

Question 26

With ON bipolar cells when the rod is continuously releasing glutamate what happens? Is it dark or light?

Answer 26

ON bipolar cell is inhibited; dark

Question 27

With ON bipolar cells when the rod is not releasing releasing glutamate what happens? Is it dark or light?

Answer 27

ON bipolar cell is activated; light

Question 28

What do ON center/OFF surround and OFF center/ON surround receptive fields do?

Answer 28

help to increase contrast, make borders between objects, can localize where the light is

Question 29

If there is an injury to the optic nerve which visual field will have defect?

Answer 29

both

Question 30

If there is an injury to the optic chiasm what kind of visual field defect will there be?

Answer 30

both nasal portions of visual fields with have defect

Question 31

The right visual field is made up by the _ nasal and _ temporal zones

Answer 31

R; L

Question 32

The left visual field is made up by the _ nasal and _ temporal zones

Answer 32

L; R

Question 33

The lateral genticulate nucleus is present where in the brain?

Answer 33

in the thalamus

Question 34

Ganglion cells with the photopigment melanopsin are responsible for what action of the pupils?

Answer 34

pupillary light reflex

Question 35

The pupillary light reflex starts with afferents traveling in ganglion cell axons to the ______

Answer 35

pretectal nucleus of the midbrain

Question 36

The pupillary light reflex goes from the pretectal nucleus of the midbrain (now to efferent) to the ____ nucleus and then out to the short ciliary nerves

Answer 36

Edinger-Westphal

Question 37

In the ______, melanopsin-containing ganglion cells send information to the suprachiasmatic nucleus in the hypothalamus (the hypothalamus regulates circadian rhythms)

Answer 37

sleep-wake cycle

Question 38

Melatonin receptors are found in the ____

Answer 38

superchiasmatic nucleus

Question 39

Melatonin acts as a ____signal

Answer 39

dark

Question 40

Light coming in ___ melatonin

Answer 40

inhibits

Question 41

_____ are quick, simultaneous movements of both eyes in the same direction

Answer 41

saccades

Question 42

saccades are the mechanism for ____, ____, and ____

Answer 42

fixation, scanning, and rapid eye movement

Question 43

______ allow the eyes to closely follow a moving object

Answer 43

smooth pursuit eye movements

Question 44

A problem with saccades most likely indicates a ___ injury

Answer 44

CNS

Question 45

The ____ reflex is the movement of the eyes in response to head movement

Answer 45

vestibulo-ocular