exam one (eye)

Question 1

over ___ of the human cortex is involved in visual perception

Answer 1

1/3

Question 2

electromagnetic radiation visible to the eye

Answer 2

light

Question 3

measurement from trough to peak in a single wave (determines brightness and intensity)

Answer 3

amplitude

Question 4

distance from peak to peak

Answer 4

wavelength

Question 5

number of peaks per unit time (determines color)

Answer 5

frequency

Question 6

radio waves and orange-red colors (hot) have ____ wavelength/energy

Answer 6

low

Question 7

bouncing of light rays off a surface

Answer 7

reflection

Question 8

transfer of light energy to a particle or surface

Answer 8

absorption

Question 9

bending of light rays

Answer 9

refraction

Question 10

light passes through ____ and then enters the pupil, and is focused by the ____ on the ____

Answer 10

cornea; lens; retina

Question 11

in visual processing, the ____ is step one

Answer 11

retina

Question 12

the ___ ____ ____ of the thalamus is the first relay center of light energy

Answer 12

lateral geniculate nucleus

Question 13

the ___ ___ ___ is responsible for image processing and memory

Answer 13

primary visual cortex

Question 14

amount of spaced viewed by the retina when the eye is fixated straight ahead

Answer 14

the visual field

Question 15

what does the overlap of the human eyes allow humans to be good at?

Answer 15

depth perception

Question 16

what is the function of the cornea?

Answer 16

bends incoming light, by focusing light on retina

Question 17

changing the shape of the lens is known as

Answer 17

accommodation

Question 18

the ___ physically changes shape, which allows extra focusing power

Answer 18

lens

Question 19

___ additional refraction necessary for distant objects

Answer 19

little

Question 20

greater refraction is needed for focus on ____ objects (this causes a fat lens)

Answer 20

near

Question 21

people with ____ can’t bring distant objects into clear focus

Answer 21

myopia

Question 22

people with ____ can’t focus on nearby objects

Answer 22

hyperopia

Question 23

the ___ ___ ___ controls entry of light

Answer 23

pupillary light reflex

Question 24

area within the macula that marks the center of the retina and the area of highest visual acuity

Answer 24

fovea

Question 25

area of retina with relatively few blood vessels

Answer 25

macula

Question 26

direction of the light message is

Answer 26

photoreceptors to horizontal cells to bipolar cells to amacrine cells to ganglion cells (P.H.B.A.G)

Question 27

receive input from photoreceptors, project to bipolar cells

Answer 27

horizontal cells

Question 28

receive input from bipolar cells

Answer 28

amacrine cells

Question 29

rods and cones have three main regions, what are they?

Answer 29

outer segment, inner segment and synaptic terminal

Question 30

the outer segment of a rod contains more ___ because of high light sensitivity.

Answer 30

disks

Question 31

____ are responsible for visual acuity

Answer 31

cones

Question 32

the fovea is a "pit" where there are only ____ and highest visual ____

Answer 32

cones; acuity

Question 33

the ratio of cones to ganglion cells is ___ for a clear message

Answer 33

1:1

Question 34

there is a ____ ratio of rods to cones

Answer 34

higher

Question 35

the peripheral is more sensitive to ____

Answer 35

light

Question 36

cones are ____ while rods are not because they focus on light

Answer 36

accurate

Question 37

what structure converts electromagentic radiation to neural signals

Answer 37

photoreceptors

Question 38

what are the three main regions of the photreceptor

Answer 38

outer, inner, synaptic terminal

Question 39

true action potential starts with the ___ cells

Answer 39

ganglion

Question 40

the outer segment of the photoreceptor contains what

Answer 40

disks with photopigment (rhodopsin in rods)

Question 41

the inner segment of the photoreceptor contains what

Answer 41

cell body

Question 42

____ energy activates photopigment (receptor) which stimulates the G protein, which is called what?

Answer 42

light, transducin

Question 43

what does transducin do

Answer 43

activates effector enzyme (phosphodiesetrase)

Question 44

The phosphodiesetrase decreases the second messenger which decreases

Answer 44

Na+ and GLU release

Question 45

in the dark _____ is bound but not activated

Answer 45

rhodopsin

Question 46

rod outer segments are _____ in the dark, why?

Answer 46

depolarized; elevated cGMP keeps Na+ open which in turn depolarizes the inner segment and increases GLU release

Question 47

rod outer segments are _____ in the light, what is activated?

Answer 47

hyperpolarized, retinal

Question 48

mixture of wavelengths produces all colors of the rainbow by activating the three different cones

Answer 48

trichromatic theory

Question 49

what is the fast small contribution to light adjustment

Answer 49

pupillary reflex

Question 50

how do your eyes adjust to light (large contribution)

Answer 50

increased cGMP allows Na and Ca channels to open back up (takes 5-10 minutes)

Question 51

how do your eyes adjust to dark (large contribution)

Answer 51

regeneration of "unbleached" rhodopsin

Question 52

____ is inactive in the dark

Answer 52

retinal

Question 53

in the light absorbed light causes a conformational change activating the ____ which "bleaches" it.

Answer 53

opsin

Question 54

photoreceptors and bipolar cells produce only ____ changes in membrane potentials

Answer 54

graded

Question 55

retinal non-ganglion cells function

Answer 55

depolarize or hyperpolarize

Question 56

retinal ganglion cells fucntion

Answer 56

change in frequency of action potentials

Question 57

ON-center bipolar cell is ____ by light on the receptive fields via direct pathway

Answer 57

depolarized

Question 58

ON-center bipolar cell is ______ by light on the receptive field surround via indirect pathway

Answer 58

hyperpolarized

Question 59

when are OFF-center bipolar cells maximally active

Answer 59

when light is only in the surround

Question 60

bipolar cell receptive fields code for patches and locations of what

Answer 60

light and dark

Question 61

ON-center on the bipolar cells are ____ signal detectors

Answer 61

light

Question 62

OFF-center on the bipolar cells are ____ signal detectors

Answer 62

dark

Question 63

ganglion cell axons that leave by the optic nerve generate action potentials, whats that called?

Answer 63

frequency coding

Question 64

type of ganglion cell that is large in size, large receptive fields and fast acting

Answer 64

M-type (Magno)

Question 65

type of ganglion cell that is small in size, small receptive fields, and are wavelength specific

Answer 65

P-type (Parvo)

Question 66

explanation of color vision that emphasizes the importance of the opposition of colors

Answer 66

opponent-process theory