eyes etc

Question 1

where is the highest concentration of cones located

Answer 1

in the fovea of the retina

Question 2

where is the highest concentration of rods located

Answer 2

at the edges of the eye

Question 3

describe spacial summation

Answer 3

• for rods
  -the stimulation of several impulses to one bipolar neurone at once
  -means that threshold is more likely to be reached
• and an action potential will be reached

Question 4

what are rods described as having

Answer 4

-high visual sensitivity
-low visual acuity

Question 5

what are cones said to have

Answer 5

-low visual sensitivity
-high visual acuity

Question 6

when are rods used

Answer 6

in dim light

Question 7

when are cones used

Answer 7

bright light
-for colours

Question 8

why do cones have high visual acuity

Answer 8

because they dont have spacial summation
- most cones synapse with only one bipolar neurone
-a separate set of impulses is sent to the brain

Question 9

what does it mean for cones to have a high visual acuity

Answer 9

-provides a no blurring affect

Question 10

why and what ratio do cones have

Answer 10

1:1

-each part of an image is being detected by a different cell

Question 11

what does it mean for rods to have low visual acuity

Answer 11

-they share a bipolar neurone
-several rods may be stimulated
-so the brain only receives one set of impulses from a large information

Question 12

why do rods have high visual sensitivity

Answer 12

-rhdopsin is broken down at lower light intensities
-several rods synapse with one bipolar neurone
-meaning threshold is more likely to be reached