CNS FA17- Visual System

Question 1

Where are the lateral protrusions that form the optic cup?

Answer 1

The diencephalon

Question 2

The ______ forms the retina?

Answer 2

Optic cup

Question 3

The optic cup is connected to the diencephalon via

Answer 3

The optic stalk

Question 4

The optic stalk becomes

Answer 4

Optic nerve

Question 5

T/F: The retina and optic nerve are derived directly from diencephalon

Answer 5

True

Question 6

Is the Optic nerve surrounded by CSF

Answer 6

Yes

Question 7

What are the retinal cell types?

Astrick the main three

Answer 7

Photoreceptors *

Bipolar neurons *

Ganglion cells *

Horizontal cells

Amacrine cells

Question 8

Which retinal cells types are a part of the neuron chain that converts light into recognizable images?

Answer 8

Photoreceptors —>

Bipolar neurons —>

Ganglion cells —>

Brain

Question 9

Which are the retinal interneuron cells?

Answer 9

Horizontal

Amacrine

Question 10

Which retinal cell receives the outside stimuli?

Answer 10

Photoreceptors

Question 11

Type of photoreceptors that is Rod shaped and located at the periphery of the retinal.

They do not respond to light but respond to movement and Shapes and forms

Answer 11

Rods

Question 12

Type of photoreceptors that is cone shaped, more numerous in the center of the retina and need light to work.

Stimulated by color

Answer 12

Cones

Question 13

Retinal cells that are relay neurons that come in two types (atleast)

Answer 13

Bipolar neurons

Question 14

Two types of bipolar neurons?

Answer 14

On-excite

Off-inhibit

Question 15

Retinal cell type whose axons form the optic nerve.

It is considered projection neuron, output neurons and leaves the retina!

Answer 15

Ganglion

Question 16

Where are the rods and cones located within the retina?

Answer 16

Outer nuclear layer

Question 17

Outer synaptic/ outer plexiform layer is the location of which action in the visual chain?

Answer 17

Where Photoreceptors synapse with bipolar cells

Question 18

Location of horizontal cells in the retinal?

Answer 18

Outer synaptic/plexiform layer

Question 19

Ganglion cell location

Answer 19

Ganglion cell layer

Question 20

Bipolar neurons (rod and Cone) and inter plexiform cell are located where in the retina?

Answer 20

Inner nuclear layer

Question 21

What action occurs in the inner synaptic layer of the retina?

Answer 21

Bipolar synapses with ganglion cells

Question 22

Amacrine cell location

Answer 22

Inner synaptic layer/plexiform

Question 23

Function of the horizontal cells

Answer 23

Fine tuning of depth

Question 24

Function of amacrine cells

Answer 24

Contrast enhancement

Motion detectors

Question 25

How does light come into hit the rods and cones?

Answer 25

Optic nerve fiber layer —> Ganglion cell layer —> Inner plexiform layer —> Inner nuclear layer —> Outer plexiform layer —> Outer nuclear layer —> Rod and cone layer

Question 26

Light travels through the many layer except at this point because the retinal cells other than the photoreceptors are pushed to the side and light directly hits it?

Answer 26

Fovea centralis

Question 27

T/F: The fovea centralis is the center of the retina

Answer 27

True

Question 28

From retina where does stimulus go?

Answer 28

Retina —> lateral geniculate body/nucleus in thalamus —> visual cortex

Question 29

Optic tract splits into two strias. This stria of the optic tract goes to lateral geniculate nucleus, then onto the cortex

Answer 29

Lateral stria

Question 30

The optic tract splits into two strias: This stria goes to the superior colliculus, pretectal area and suprachiasmatic nucleus

Answer 30

Medial stria

Question 31

Function of superior colliculus in the visual pathway

Answer 31

Eye or head movement towards the stimulus

Question 32

Pretectal area function in the visual pathway

Answer 32

Pupillary light reflex

Question 33

Suprachiasmatic reflex (part of hypothalamus) function in visual pathway

Answer 33

Sleep/wake cycle

Question 34

T/F: IT matters what you are looking at as it pertains to the superior colliculus function

Answer 34

False

Question 35

T/F: Pretectal areas and suprachiasmatic nucleus focus of the amount of light coming in

Answer 35

True

Question 36

Definition: Stimulus that is being seen from outside world

Answer 36

Visual field

Question 37

Which stria of the optic tract split discerns what is being seen?

Answer 37

Lateral stria

Question 38

Definition: How stimulus being seen hits the retina

Answer 38

Retinal field

Question 39

Does the nasal retinal/ medial retinal field cross over? Where?

Answer 39

Crosses over at the optic chiasm

Question 40

Does thelateral retinal field/temporal retinal field cross over?

Answer 40

No

Question 41

Things that are temporal in the visual field hit which aspect of the retinal field as the pass through the lens?

Answer 41

Medial/nasal retinal field

Question 42

Things that are central in the visual field hit which aspect of the retinal field as they pass through the lens?

Answer 42

The lateral/temporarily retinal field

Question 43

Visual cortex is located

Answer 43

Occipital lobe surrounding calcarine sulcus

Question 44

What are the six layers of the lateral geniculate nucleus?

Answer 44

4 are parvocellular neurons 2 are magnocellular (1st 2)

Question 45

The first two layers of the lateral geniculate nucleus respond to

Answer 45

Movement Form/shape

Question 46

The remaining 4 layers of the lateral geniculate nucleus responds to

Answer 46

Color Some shape and form

Question 47

The two magnocellular layers of the lateral geniculate nucleus get their input from

Answer 47

Rods

Question 48

The 4 parvocellular layers of the lateral geniculate nucleus receive input from

Answer 48

Cones

Question 49

Which layers of the lateral geniculate nucleus receive contralateral input?

Answer 49

1 4 6

Question 50

Layers of the lateral geniculate nucleus that receives ipsilateral input

Answer 50

2 3 5

Question 51

The origin and insertion of the optic radiations in the visual pathway?

Answer 51

Lateral geniculate nucleus —> visual cortex

Question 52

All of the lamina of the lateral geniculate nucleus go to which layer of the visual cortex?

Answer 52

Layer four of visual cortex

Question 53

Layer four of the visual cortex receives all the input from lateral geniculate nucleus into organizing input in which way?

Answer 53

Ipsilateral Contralateral

Question 54

Neurons in lamina 4 project fibers where

Answer 54

Other layers of visual cortex

Question 55

The upper three layer of the visual cortex (3,2,1) send the input where?

Answer 55

Extrastriate cortical region AKA association visual cortex

Question 56

Layer 5 of the visual cortex sends the input where and what is its function?

Answer 56

Superior colliculus Reinforce looking at stimulus, consciously Slightly delayed

Question 57

Function of associational visual cortex/ extrastriate cortical regions

Answer 57

Makes association between previous stimuli and new stimulus

Question 58

Layer 6 of the visual cortex sends input where and what is its function?

Answer 58

To lateral geniculate nucleus Negative reflex for negative feedback loop

Question 59

Cut through optic nerve results in

Answer 59

Loss of vision in one eye | Total blindness of ipsilateral eye

Question 60

Cut through the optic chiasm results in

Answer 60

Medial retinal field is lesioned so you can’t see what’s lateral in visual field (Ispilateral nasal hemianpsia) (Tunnel vision)

Question 61

Cut through optic tract results in

Answer 61

Bitemporal heteronymous hemianopsia

Question 62

Meyer loop

Answer 62

Contralateral fibers of optic tract that go into the temporal lobe

Question 63

Cut through optic radiation closer to visual cortex results in

Answer 63

Contralateral homoymous hemianopsia with macular sparring

Question 64

Why does macular sparing occur?

Answer 64

Receive information from fovea so it has a higher representation in the cortex