Vision II

Question 1

Photoreceptors

Answer 1

• Rods and Cones
• Transmit signals from the Plexiform layer
• Synapse w/ Bipolar and Horizontal cells

Question 2

Plexiform Layer

Answer 2

Layer of SYNAPTIC connections

Question 3

The Neurons that make up the Pure ROD Vision

Answer 3

1. Rods
2. Bipolar Cells
3. Amacrine Cells
4. Ganglion Cells

Question 4

How much decussation occurs in the Optic Chiasm?

Answer 4

50%

Question 5

Amacrine Cells an Neurotransmitters

Answer 5

• 8+ more kinds of NT

- GABA, Glycine, Dopamine, ACh and Indolamine ALL INHIBITORY

Question 6

Ganglion Cells

Answer 6

• Transmit signals from the retina to the Brain

- Axons make up the OPTIC NERVE

Question 7

What controls how much of the signal is allowed to Pass to the Cortex?

Answer 7

Lateral Geniculate Nucleus

Question 8

The Peripheral Retina is more sensitive to what kind of light?

Answer 8

Weak

Question 9

Bipolar Cells

Answer 9

• Transmit signals from Rods, Cones, and Horizontal cells

- Synapse w/ Amacrine and Ganglion cells

Question 10

What Geniculate Nucleus Layers receive signals from the LATERAL Half of the opposite retina?

Answer 10

II, III, and V

2, 3, 5

Question 11

How many layers are in the VISUAL Cortex?

Answer 11

6

Question 12

Accommodation in CHILDREN

Answer 12

• Refr Power of lens can Increase from 20-34

14 diopters

Question 13

Axons of the Ganglion Cells

Answer 13

• Make up the OPTIC NERVE

Question 14

Is the Output of Horizontal Cells inhibitory or Excitatory?

Answer 14

• Inhibitory

Lateral Inhibition

Question 15

Y Ganglion Cells

1. Diameter Size of Axon
2. Transmission
3. Characteristics

Answer 15

1. LARGE Diameter
2. 50m/sec (Fast)
3. Responds to RAPID changes in Visual Image

Question 16

Presbyopia

Answer 16

The decrease in ability for the eye to focus on NEAR objects

Question 17

Horizontal Cells

Answer 17

• Transmit Signals from Rond and Cones to Bipolar cells

- Output is ALWAYS Inhibitory
Lateral Inhibition

Question 18

T/F: Some Amacrine Cells respond when a Light is turned On or Off

Answer 18

True

Question 19

Accommodation in OLD Adult

Answer 19

• Lens becomes Large and Thick
• Power decreases to Less than 2 diopters by 45-50yrs
• Power decreases to 0 by age 70

Question 20

W Ganglion Cells

1. Diameter Size of Axon
2. Transmission
3. Field size

Answer 20

• Small AXON Diameter
• Transmits 8m/Sec (SLOW)
• BROAD Fields

Question 21

What Retinal cells Transmit signals to the OUTER Plexiform

Answer 21

• Photoreceptors

- Horizontal cells

Question 22

What is the ONLY retinal cells that transmit AP?

Answer 22

Ganglion Cells

Question 23

What Dorsal Lateral Geniculate layers Transmit only COLOR?

Answer 23

Layers III -> VI

Question 24

What Geniculate Nucleus Layers receive signals from the MEDIAL Half of the opposite retina?

Answer 24

I, IV, and VI

1, 4, and 6

Question 25

Inter-Plexiform Cells

Answer 25

- Transmit from Inner Plexiform Layer to the Outer Plexiform layer (Retrograde) - Lateral Inhibition

Question 26

What ganglion cell is responsible for ALL Color Vision?

Answer 26

X Ganglion cells

Question 27

How many rods converge on a single optic fiber in the peripheral regions of the Retina?

Answer 27

200

Question 28

Dorsal Lateral Geniculate Nucleus

Answer 28

- Receives Input from the OPTIC Nerves | - Relays information from the Optic tract to the Visual Cortex

Question 29

X Ganglion Cells 1. Diameter Size of Axon 2. Transmission 3. Field size

Answer 29

- Medium Diameter - 14m/sec (Medium) - SMALL Fields * EVERY X ganglion cell receives an input from at lease One CONE cell *

Question 30

Three Neurons in the Foveal Region

Answer 30

- Cones - Bipolar Cells - Ganglion Cells

Question 31

What Retinal cells Transmit signals to the Inner Plexiform

Answer 31

- Bipolar cells | - Amacrine cells

Question 32

What Dorsal Lateral Geniculate layers Transmit only BLACK and WHITE

Answer 32

Layers I and II

Question 33

How many Ganglion Cells are there? What are they?

Answer 33

- Three types | - W, X, and Y

Question 34

Layers of the Retina

Answer 34

1. Photoreceptors 2. Horizontal cells 3. Bipolar Cells 4. Amacrine Cells 5. Ganglion Cells

Question 35

Most Amacrine cells are what?

Answer 35

- INTERNEURONS | - Help analyze Visula signals BEFORE they leave the retina

Question 36

Amacrine Cells

Answer 36

- Transmit signals from Bipolar to Ganglion cells | - Transmit signals w/in Inner Plexiform

Question 37

How Many Layers in the Lateral Geniculate Nucleus?

Answer 37

6

Question 38

Geniculo-Calcarine Fibers terminate mainly in what Visual Cortex Layer?

Answer 38

Layer IV (4)

Question 39

Ganglion Cells by percentage.

Answer 39

W: 40% X: 55% Y: 5%