Lecture 3 - Vision

Question 1

What is meant by the term visual field

Answer 1

The region of space viewed by the retina when the eye is fixated straight ahead

Question 2

Lesion in right optical nerve results in blindness in which area?

Answer 2

Right temporal vision

Question 3

Lesion in the left optical tract results in blindness in which area?

Answer 3

Right hemi-field

Question 4

Lesion in the optic chiasm results in blindness in which area?

Answer 4

Both temporal vision

Question 5

Define receptive field in terms of vision

Answer 5

Receptive field is region in the visual field when illuminated elicit a change in resting membrane potential or increase in firing rate of AP

Question 6

Which retinal cells listed below do NOT fire action potentials:

• Ganglion cells
• Bipolar cells
• Photoreceptor cells

Answer 6

Photoreceptors and bipolar cells

Question 7

Name two supporting cells which influence the activity of the retinal cells

Answer 7

Amacrine cells: received input from bipolar cells and affect the activity of bipolar and ganglion cells

Horizontal cells: received input from photoreceptor cells and influence activity of photoreceptors and bipolar cells