Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuro > Ch 9: the eye > Flashcards

Ch 9: the eye Flashcards

1
Q

conjunctiva

A

mucous membrane that covers front of eyes and lines inside of eyelids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

three eye layers

A

fibrous, vascular, retinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

sclera

A

white layer of dense connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cornea

A

transparent coat that covers the iris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

choroid

A

highly vascularized internal lining of sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ciliary body

A

anterior vascular layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

iris

A

colored portion of eye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

pupil

A

hole in center of iris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

dilation

A

regulated by sympathetic neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

constriction

A

regulated by parasympathetic neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

macula lutea

A

yellow spot at retinal posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

fovea centralis

A

contains only cones; highest resolution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

optic disc

A

exit site of optic nerve (blind spot)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

vitreous humor

A

fills space between retina and lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

diopter

A

reciprocal focal distance; measure of refractive power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

accomodation

A

ability to change refractive power of lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

visual field

A

total amount of space that can be viewed by the retina when the eye is fixed straight ahead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

visual acuity

A

ability to distinguish two nearby points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

horizontal cells

A

receive input from photoreceptors and project to bipolar cells and other photoreceptors

20
Q

amacrine cells

A

receive input from bipolar cells and project to ganglion cells, bipolar cells, or other amacrine cells

21
Q

rods

A
  • 92 million/retina
  • 1000 times more sensitive than cones
  • vision in dim light
  • black and white vision
22
Q

cones

A
  • 5 million/retina
  • vision in bright light
  • color vision
23
Q

central vision

A
  • greater resolution in daylight
  • blind in dim light
  • better in discriminating colors
24
Q

peripheral vision

A

more sensitive in dim light

25
Q

photopigments

A
  • opsin portion: 7 transmembrane GPCRs
  • retinal portion: light absorbing area
26
Q

phototransduction

A

conversion of light energy to membrane potential

27
Q

phototransduction (dark)

A
  • outer segments of the rod are depolarized in the dark
  • guanylyl cyclase produces cGMP
  • cGMP opens Na+ channels, causing Na+ inflow (depolarization)
  • ca2+ remain open
  • ca2+ influx triggers glutamate release
  • glutamate causes inhibition of postsynaptic potential
28
Q

phototransduction (light)

A
  • light causes conformational change of cis-retinal to trans-retinal
  • trans-retinal separates from opsin
  • transducin is activated
  • transducin activates cGMP phosphodiesterase, degrades cGMP
  • cGMP-gated Na+ channels close, causing hyperpolarization
  • Ca2+ channels close, decreasing Ca2+ influx
  • glutamate release is shut off
  • bipolar cells are activated and stimulate ganglion cells
29
Q

_________ cells receive input

A

bipolar

30
Q

_________ cells fire APs

A

ganglion

31
Q

direct input pathway

A

light → photoreceptors → bipolar cells

32
Q

indirect input pathway

A

light → photoreceptor cells → horizontal cells → bipolar cells

33
Q

receptive field

A

provides direct input

34
Q

receptive surround

A

provides indirect input

35
Q

M-type cells

A
  • 5%
  • conduct APs more rapidly
36
Q

P-type cells

A

90%

37
Q

nonM-nonP-type cells

A

5%

38
Q

ipRGCs

A
  • use melanopsin as photopigment
  • depolarize to light
  • involved in circadian rhythms
39
Q

in the eye, the ______ and lens refract light rays to focus them on the retina.

A

cornea

40
Q

the sympathetic nervous system stimulates contraction of _______ muscles and ______ the pupil’s size.

A

dilator pupillae; increases

41
Q

the parasympathetic nervous system stimulates contraction of _______ muscles and ______ the pupil’s size.

A

sphincter pupillae; decreases

42
Q

sequence of visual information transfer in the retina

A

photoreceptors → bipolar cells → ganglion cells

43
Q

which part of the photoreceptors contains photopigments?

A

outer segment (discs and folds)

44
Q

light stimulus _______ glutamate release from photoreceptors and induces _______ of ON bipolar cells.

A

decreases; depolarization

45
Q

light stimulus _______ glutamate release from photoreceptors and induces _______ of OFF bipolar cells.

A

decreases; hyperpolarization

Neuro (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions