Vision

Question 1

What is happening during presbyopia

Answer 1

near point of vision recedes

Question 2

how is the image on retina in comparision to IRL

Answer 2

inverted and reversed

Question 3

near response when someone looks at a near object

Answer 3

accommodation
convergence of visual axes
pupils constrict

Question 4

what is unique about the optic disc

Answer 4

it’s a blind spot

Question 5

scotoma

Answer 5

a visual field defect

Question 6

what is responsible for scotopic vision

Answer 6

rods

Question 7

what is responsible for phototopic vision

Answer 7

cones

Question 8

what type of vitamin deficiency is associated with night blindness

Answer 8

vit A

Question 9

what do photosensitive retinal ganglion cells contain

Answer 9

melanopsin

Question 10

function of melanopsin

Answer 10

measure overall light intensity

Question 11

what is happening in the dark

Answer 11

channels tha tpermit entry of Na+ and Ca++ are help open by cGMP

Question 12

what happens when the channels that permit entry of Na+ and Ca++ are open

Answer 12

depolarization, release of neurotranmiter

Question 13

capture o fa photon activates what

Answer 13

visual pigment (ex - rhodopsin)

Question 14

when do photoreceptors hyperpolarize

Answer 14

when K+ leaves cell

Question 15

what is the retina formed by embryologically

Answer 15

evagination of the diencephalon

Question 16

what makes up the optic nerve and tract

Answer 16

axons of ganglion cells

Question 17

what are axons in the optic nerve/tract myelinated by

Answer 17

oligodendrocytes

Question 18

where does preliminary processing of visual information take place

Answer 18

in retina

Question 19

what are the only things that produce APs in the eye

Answer 19

ganglion cells

Question 20

what neurotransmitter is released by photoreceptors

Answer 20

glutamate

Question 21

what is the result of glutamate

Answer 21

it can excite or inhibit bipolar cells

Question 22

what is the receptive field of a neuron

Answer 22

the area of retina from which the neuron can be influenced

Question 23

what is the organization of bipolar celll receptive fields

Answer 23

center-surrond

Question 24

what do bipolar cells response better to

Answer 24

properly position spot of light than to even illumination

Question 25

Where do retinal fiberss terminate

Answer 25

lateral geniculate of thalamus suprachiasmatic nucleus of hypothalamus pretectal nucleus superior colliculus

Question 26

what is the function of the retinal cells that terminate in the lateral geniculate of thalamus

Answer 26

relays to visual cortex and recieves input from the visual cortex

Question 27

where do most retinal cells terminate

Answer 27

LGN

Question 28

what is the function of retinal cells that terminate in the suprachiasmatic nucleus of hypothalamus

Answer 28

circadian rhythms

Question 29

what is the function of retinal cells that terminate in the pretectal nucleus

Answer 29

mediate pupillary light reflexes

Question 30

what is the function of retinal cells that terminate in the superior colliculus

Answer 30

in response to visual stimuli can cause eyes, head, and body to turn towards stimuli

Question 31

where do ganglion cell axons from the nasal retina cross

Answer 31

at optic chiasm

Question 32

what causes bitemporal hemianopsia

Answer 32

damage to central part of optic chiasm

Question 33

what causes homonymous hemianopsia

Answer 33

contralateral to optic tract damage

Question 34

what causes superior-quadrant anopsia

Answer 34

contralteral to lesion of Meyer's loop

Question 35

What is the dorsal pathway responsible for

Answer 35

analysis of motion and relative posititions of object in visual scene

Question 36

what is ventral stream responsible for

Answer 36

high level form vision and object recognization

Question 37

prosopagnosia

Answer 37

visually identifying faces

Question 38

object agnosia

Answer 38

problem identifying objects

Question 39

cerebral akinetopsia

Answer 39

loss of ability to see motion

Question 40

short wavelength cone

Answer 40

blue

Question 41

middle wavelength cone

Answer 41

green

Question 42

long wavelength cone

Answer 42

red

Question 43

what is red green color blinded caused by

Answer 43

missing either red or green cone

Question 44

what do red green color blindness have trouble distinguishing between

Answer 44

green, yellow, orange, red

Question 45

monochromatopsia

Answer 45

either you have 1 cone or no cones

Question 46

how do you test for color blindness

Answer 46

ishihara charts

Question 47

where are the genes for red and green cone pigments

Answer 47

X chromosome

Question 48

where is teh gene for blue cone pigmenet

Answer 48

chromosome 7

Question 49

where is the gene for rhodopsin

Answer 49

chromosome 3

Question 50

stereoscopic vision

Answer 50

requires binocular vision. can make use of binocular disparity for near objects

Question 51

strabismus

Answer 51

squint or cross eyes

Question 52

amblyopia

Answer 52

brain ignores the suppressed eye

Question 53

what happens if you have retinal detachment

Answer 53

vitreous body will seep behind retina, cause further detachment

Question 54

fovea

Answer 54

highest acuity

Question 55

where do the major blodo vessels orginate from

Answer 55

optic disk

Question 56

foveola

Answer 56

center of fovea

Question 57

what is unique about foveola

Answer 57

avascular

Question 58

where are cones located

Answer 58

center of fovea

Question 59

what cones are located in the very center of the fovea

Answer 59

red and green

Question 60

where is the highest concentration of rods

Answer 60

just outside the fovea

Question 61

mesopic vision

Answer 61

rods and cones (moonlight)

Question 62

quadrantopsia

Answer 62

blind in one quadrant

Question 63

what is quadrantopsia caused by

Answer 63

lesion in meyer's loop or superior radiations on contraltareal side

Question 64

what causes hemianopsia with macular sparing

Answer 64

lesion in optic radiations