Vision Physiology Flashcards Preview

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Flashcards in Vision Physiology Deck (16):
1

What must the photons be transduced into?

Electrical signals

2

What do the photoreceptors do?

Convert electromagnetic radiation to neural signals

3

What are the 4 main regions of the photoreceptors?

Outer segment
Inner segment
Cell body
Synaptic terminal

4

What does all-trans-Retinal lead to?

Closure of cGMP - gated Na+ channel, with lowered Na comes hyperpolarization

5

Is there more glutamate in the dark or in the light?

Dark

6

What is the receptive field?

Part of the retina that needs to be stimulated to elicit action potentials from a ganglion cell

7

When are Rods used more?

In dim light

8

When are cones used more?

In normal daylight

9

Where is the more convergence?

In rods, increasing sensitivity but decreasing acuity

10

Do ganglion cells cause changes in membrane potential or produce action potentials?

Produce action potentials

11

Where do horizontal cells receive input from?

Photoreceptors and project to other photoreceptors and bipolar cells

12

Where do Amacrine cells receive their input from?

Bipolar cells and project to ganglion cells, bipolar cells and other amacrine cells

13

The visual cortex is mapped out precisely, this is called what?

Visuotopic organization

14

What do the magnocellular LGN neurons protect?

Layer IVC alpha

15

What do the Parvocellular LGN neurons protect?

IVC beta

16

What do the konicellular LGN axons do?

Bypass layer IV to make synapses in layers 2 and 3 (blobs, visible after cytochrome oxidase staining)