Vision

Question 1

T/F- Macula controls central vision and has high visual acuity

Answer 1

True

Question 2

What factors limits visual acuity?

Answer 2

Neuronal and optic factors

Question 3

What are the layers in the retina that the light has to pass through?

Answer 3

ganglion layer, bipolar cells, and the photoreceptors

Question 4

what are some properties of rods?

Answer 4

Night vision, very sensitive, no colour vision, 95% of photoreceptors are rods, one type only

Question 5

what are some properties of cones?

Answer 5

day vision, less sensitive, three types, allow color vision, densest in fovea

Question 6

T/F- There are no rods in macula densa

Answer 6

True

Question 7

T/F- Optic nerve contains photoreceptors

Answer 7

False- They dont

Question 8

Rods contain ___ whereas cones contain ____

A) Conopsins, rhodopsins
B) Rhodopsins, Conopsins

Answer 8

B) Rhodopsins, Conopsins

Question 9

When Vitamin A gets hit by light, it changes conformation from _______ to ______

A) 11-trans-retinal, 11-cis-retinal
B) 11-cis-retinol, 11-trans-retinol
C) 11-cis retinal, 11-trans-retinal
D) 11-trans-retinol, 11-cis-retinol

Answer 9

C) 11 cis retinal to 11 trans retinal

Question 10

Photoreceptors are ______ by light, using ____ as their neurotrasmitter

A) depolarised, glutamate
B) hyperpolarised, glutamate
C) depolarised, GABA
D) hyperpolarised, GABA

Answer 10

B) hyperpolarised, glutamate

Question 11

In the dark, ____ gates a sodium channel causing continuous influx of ______ ions. This causes depolarisation of cell

Answer 11

cGMP, sodium

Question 12

In the light, ____ breaks down to ___, and the cell is ____ because ____ no longer gates the channel.

A) GMP, cGMP, Hyperpolarise, GMP
B) cGMP, GMP, Hyperpolarised, cGMP
C) cGMP, cGMP, Depolarised, cGMP
D) GMP, GMP, Depolarised, GMP

Answer 12

B) cGMP, GMP, Hyperpolarise, cGMP

Question 13

What enzyme activates and breaksdown cGMP to GMP in response to light?

Answer 13

Phosphodiesterase

Question 14

Retina is wired up through the _______, and cells critical to this is ______ and _______

A) Through pathway, Horizontal cells, Vertical Cells
B) Through pathway, horizontal cells, amacrine cells
C) Follow through pathway, horizontal cells, amacrine cells
D) None of the above

Answer 14

B)

Question 15

Bipolar cells contain 10 different types; ___ and ___. It is important for ______ and ____ vision.

Answer 15

1* rod cell, 9* cone-bipolar cells, spatial vision, colour vision

Question 16

Ganglion cells are the only type of cells to? What neurotransmitter do they release?

Answer 16

Only cell type to fire Ap’s. Glutamate

Question 17

T/F. Ganglion cells respond to light by either increasing or decreasing their potential firing rate.

Answer 17

True

Question 18

What is a receptive field of a ganglion cell?

Answer 18

Area of retina that when stimulated with light changes the cells’ membrane potential. The way they respond depends on where you shine on that receptive field

Question 19

T/F- Horizontal cells provide input and output onto photoreceptors

Answer 19

True

Question 20

What neurotransmitter do horizontal cells release? How do they respond to light>

Answer 20

GABA. Respond by hyperpolarising

Question 21

Amacrine cells are _____ cells and are importlant for _____. For the most part they are considered inhibitory cells.

A) Myelinated, focal lenght
B) Axonless, lateral inhibition
C) Axonless, lateral excitatoin
D) Myelinated, lateral inhibition

Answer 21

B

Question 22

Ganglion cells are divided into ____ and ___ cells.

Answer 22

M and P

Question 23

M cells have large/small receptive fields and are important for ______.

Answer 23

large,important for motion detection

Question 24

P cells have large/small receptive fields and are importnat for ___________

Answer 24

small, visual acuity and colour

Question 25

What is the brief sequence of the visual pathway

Answer 25

Retina–> Optic nerve–> LGN—> Optic radiation —> Visual cortex

Question 26

Axons of the ________ form the optic nerve. Fibres from left and right optic nerves form the optic chiasm. this lies at ________

Answer 26

ganglion cell, base of brain, anterior to pitutiary

Question 27

T/F- Nasal ganglion cells cross at the optic chiasm

Answer 27

True

Question 28

Optic nerve synapse at the _______

Answer 28

LGN

Question 29

LGN contains ____ layers, and contain two types of cells; ____ and _______

Answer 29

6 layers. Magnocellular layer and Parvocellular layer

Question 30

Magnocellular form layers _____ and recieve input from ____ ganglion cells

Answer 30

1 and 2, M ganglion cells

Question 31

Parvacellular form layers _____ and recieve input from ____ ganglion cells

Answer 31

3-6, P ganglion cells

Question 32

LGN neurons project to the Primary Visual Cortex, and goes to layer ____

Answer 32

4C

Question 33

Input from the LGN is segregated into small regions of the primary visual cortex called an _________

Answer 33

ocular dominance column

Question 34

M type GC/LGN input to layer ____

Answer 34

4a

Question 35

P type GC/LGN input to layer _____

Answer 35

4b

Question 36

What are the two large cortical pathways of visual processing?

Answer 36

Dorsal pathway (where?) and Ventral pathway (what?)

Question 37

Area MT is part of the _____ pathway and an area specialised for________. It recieves input from layer ____ in PVS

Answer 37

dorsal pathway, processing object motion, layer IVB

Question 38

Area V4 is critical in the ____ pathway, they have large receptive fields that are both _____ an ____ selective. It is important for ________

Answer 38

ventral pathway, orientation and color sensitive. Important for perception of shape and colour

Question 39

Area IT is a major output of _______. IT is important for ____ and _______

Answer 39

area V4, important for perception of faces