visual system

Question 1

Retina

Answer 1

• photoreceptors are at the bottom of the retina layer

- ganglion cell layer is where the nerve starts from

Question 2

Retinal encoding

Answer 2

• are 150 million photoreceptors and 1 million nerve fibres in the optic nerve
  there are horzixonantal and amacrine cells to allow inhibition of adjacent areas
• receptive field varies in size across the retina

Question 3

what is a normal visual field

Answer 3

1. ) 90 degrees temporally to central fixation
2. ) 50 degrees superiorly
3. 60 degrees inferiorly

Question 4

What is the optic chiasm?

Answer 4

• A mechanism for the purpose of fusing the mages of the two eyes. Prevents double vision

Question 5

How many layers do the lateral geniculate nucleus

Answer 5

6 layers

Question 6

How many nerve fibres are involved with just the central 30 degrees of your vision?

Answer 6

90% of fibres

Question 7

Dorsal stream

Ventral stream

Answer 7

Dorsal: where is it? where is it moving?
Ventral: I know where it is lets catch it