Lecture 9 (DONE)

Question 1

What spectrum does visible light fall on?

Answer 1

390nm - 750 nm

Question 2

What are some other waves on the electromagnetic spectrum?

Answer 2

Gamma rays, X-rays, UV rays, radar, FM, TV, shortwave, and AM

Question 3

Which way do photoreceptors face and why?

Answer 3

Backwards towards the vasculature. This is because they need the most nutrients due to it needing to turn light in to neural signals

Question 4

What does light do in the outer segment of the photoreceptors?

Answer 4

Light is absorbed by pigment in outer segment of rods and cones and triggers phototransduction.

Question 5

What are the functions and description of cones?

Answer 5

*Day vision
*Operate at high levels
*Color Vision
*High spatial resolution
*Very Dense in Fovea

Question 6

What are the functions and description of RODS?

Answer 6

*Night vision
*Operate at low levels
*Absent in fovea
*Low spatial resolution

Question 7

What are photons?

Answer 7

Particles of energy, emitted from atoms, that travel in space as a wave.

Question 8

How do we see objects?

Answer 8

The sun emits lights that is reflected off an object.

Question 9

What are the thee major neuron types in the retina?

Answer 9

Photoreceptors, Bipolar cells, Retinal ganglion cells

Question 10

What do the axons of the RGC leave the eye to form?

Answer 10

The optic nerve.

Question 11

What are photoreceptors in the retina?

Answer 11

First neurons in the visual chain that respond to light and make up images of an object in the retina.

Question 12

What are visual pigments?

Answer 12

They absorb light which result in a change in the membrane protection.

Question 13

What does the outer segment of rods and contain?

Answer 13

Visual pigment

Question 14

What is phototransduction?

Answer 14

The process in which light is turned in to a neural signal.

Question 15

Why are cones high resolution and why are rods low resolution?

Answer 15

Cones to bipolar cells are a 1 to 1 ratio wheraas rods connect to bipolar cells making them not spatially accurate.

Question 16

What is the projection for the eye to the visual cortex?

Answer 16

Retina to LGN to Visual Cortex

Question 17

What is your blind spot?

Answer 17

A point in your vision where you cannot see anything. It is where the optic nerve is.

Question 18

What is the purpose of visual pigment?

Answer 18

Visual pigment absorbs lights, which results in a change in the membrane potential.

Question 19

What is one example of your cone vision failing?

Answer 19

For the constellation called Pleiades, it’s like 7 stars. They are very dim stars. If you focus on them with your fovea, they’ll disappear. Because there’s not enough light to activate your cones. And you have to look at the right of them just so your rods are activated. Then you can see the stars.

Question 20

Why do rods have many connections compared to 1:1 in cones?

Answer 20

It is because rods work the best at night. So they want to take that very small amount of light and they want to make sure that the signal gets to the brain. So they start pooling all their inputs, so you get a bigger signal.

Question 21

How do signals from the eye go back to your brain?