Visual System Overview

Question 1

What are the 6 major parts of the Visual System?

Answer 1

1. Retina
2. Dorsal Lateral Geniculate Nucleus of the Thalamsus (dLGN)
3. Primary Visual Cortex
4. Superior Colliculus
5. Pretectum
6. Suprachiasmatic Nucleus of the Hypothalamus

Question 2

Describe the fluid dynamics of the eye

Answer 2

1. Vitreous Humor

2. Aqueous Humor

Question 3

What are the 5 cell types in the retina?

Answer 3

1. Photoreceptors
2. Bipolar
3. Ganglions
4. Horizontal
5. Amacrine

Question 4

Discuss the relationship between polarization and neurotransmitter release.

Answer 4

Photoreceptors hyperpolarize and decrease neurotransmitter release when exposed to light. Vice versa.

Question 5

What is the primary source of blood to the eye?

Answer 5

Ophthalmic branch of the internal carotid.

Question 6

What supplies the choroid layer?

Answer 6

Short and Long posterior ciliary arteries serve the photoreceptors, ciliary muscle and iris

Question 7

What supplies the inner retina?

Answer 7

Central retinal artery and vein

Question 8

What supplies the outer retina?

Answer 8

Long and short postrior ciliary arteries

Question 9

What supplies the ciliary muscle and iris?

Answer 9

Long posterior ciliary artery

Question 10

Discuss the path of light in the eye

Answer 10

The retina has an ‘inside-out’ organization; light entering the eye first passes over the ganglion cells on the inner retinal surface before reaching the photoreceptors located in the outer layer of the retina.

Question 11

What are the seven retinal layers?

Answer 11

1. Pigment Epithelium
2. Outer nuclear layer
3. Outer plexiform layer
4. Inner nuclear layer
5. Inner plexiform layer
6. Ganglion cell layer
7. Nerve fiber layer

Question 12

What are the 3 types of glial cells in the retina?

Answer 12

1. Muller glia: Retinal homeostasis
2. Microglial: Immune response to injury
3. Astrocytes

Question 13

What are 5 characteristics of Rods?

Answer 13

1. Absent from fovea
2. High sensitivity in low light
3. Scotopic-Mesopic range
4. High convergence
5. Achromatic

Question 14

What are 5 characteristics of cones?

Answer 14

1. Low sensitivity
2. Mesopic-Photopic range.
3. Low convergence
4. High density in fovea
5. High resolution