Aqueous And Vitreous Humor

Question 1

Where can you find aqueous humor?

Answer 1

Anterior and posterior chambers of the eye

Question 2

How does the aqueous humor resemble blood plasma?

Answer 2

It’s composition is similar.

Humor has less protein and glucose, but MORE lactic acid and ascorbic acid (VIT C)

Question 3

What does the aqueous humor supply?

Answer 3

Cornea and lens (they’re avascular)

Question 4

Where is aqueous humor produced?

Answer 4

In the NPE of the pars plicata of the ciliary body.

Question 5

What is the function of ascorbic acid in aqueous humor?

Answer 5

Fight bacterial infections and assists in forming collagen

Question 6

Total volume of aqueous humor? How often is it replaced?

Answer 6

0.2 microliters. Every 100 minutes!

Question 7

5 main components of the Aqueous Humor

Answer 7

1. Bicarbonate (buffer)
2. Lactic acid
3. Ascorbic acid (fight infection and detox)
4. Chlorides
5. Glucose (food)

ALL are found in blood plasma but different concentrations

Question 8

The vitreous humor is mainly composed of:

Answer 8

Hyaluronic acid and collagen.

98.5-99.7% Water!

Question 9

Vitreous humor touches the retina, so drugs can alter what 4 metabolites?

Answer 9

Magnesium Serum

Copper Serum

Zinc Serum

Selenium Serum

Question 10

Which part of the uvea produces and secretes the vitreous humor?

Answer 10

NPE of the Pars Plana

Question 11

Where is collagen content the highest in the vitreous?

Answer 11

In the vitreous base

Then posterior cortex, then anterior cortex

Lowest in the center

Question 12

What contributes to the optical transparency of the vitreous humor?

Answer 12

The fine meshwork of uniform collagen fibrils, each 8-16 mm in diameter

Question 13

What types of collagen are in the vitreous?

Answer 13

Type II, mainly 60-75%

Type IX, 25%

Type XI, 10-25%

Question 14

Which non-collagen component of the vitreous is a major structural component of the zonules?

Answer 14

Fibrillin

Question 15

Marfans syndrome is caused by mutations of:

Answer 15

Fibrillin-1

Makes sense because fibrillin makes up zonules, which hold then lens, and ectopia lentis occurs in marfans. AH-HA

Question 16

Leucine-rush glycoprotein found in the vitreous that binds growth hormones and GAGs.

Answer 16

Opticin

Question 17

All GAGs except __________ ____ are attached to a protein core.

Where are GAGs high in concentration, where are they low?

Answer 17

Hyaluronic acid

High in vitreous, low in sclera

Question 18

Is Hyaluronic acid hydrophilic of hydrophobic?

What does it do? Where is it found?

Answer 18

Hydrophilic.

Maintains the wide spacing between fibrils in the vitreous, found mostly in the posterior cortex.

We love HA as we age.

Question 19

The gel structure of the vitreous is mainly due to the integration of ________ and __________ _____

Answer 19

Collagen and hyaluronic acid

HA stabilizes the network formed by collagen.

Question 20

What is the predominant GAG in mammalian vitreous?

Answer 20

Hyaluronic acid

Question 21

Vitreous cells that are believed to synthesize HA and have phagocytic properties.

Some made up shit basically. Optometric philosophy?

Answer 21

Hyalocytes

Question 22

What forms when HA begins to degenerate in the eye? (Because the HA surround and suspends the collagen fibrils)

Answer 22

Floaters.

Collagen fibrils begin to coalesce.