Cornea - Recit

Question 1

What are the layers of the cornea?

Answer 1

ABCDE
1. (Anterior) Epithelium
2. Bowman’s Layer
3. Corneal Stroma
— Dua’s layer—
4. Descemet’s Layer
5. Endothelium

Question 2

Function of Epethilium

Answer 2

1.to obstruct the passage of foreign materials (dust, bacteria) from penetrating the layers of the cornea
2. to absorb oxygen and nutrients from the eye’s tears to provide a smooth surface layer. The nutrients that are absorbed from the tear layer are distributed to the remainder of the cornea via the epithelium

Question 3

Function of Bowman’s Layer

Answer 3

Structurally reinforces the cornea

Question 4

Basement membrane of the epithelium; transparent sheet composed of collagen fibers

Answer 4

Bowman’s Layer

Question 5

Does not get damaged easily but cannot be regenerated once damaged

Answer 5

Bowman’s Layer

Question 6

Comprises 90% of the Cornea’s thickness. It consists mainly of 78% water and 16% collagen. Does not contain any blood vessels.

Answer 6

Corneal Stroma

Question 7

Function of Descemet’s layer?

Answer 7

Serves as a protective barrier against infection and injuries

Question 8

Anchors the endothelium to the cornea, while simultaneously allowing the entry od nutrients and macromolecules into the corneal stroma

Answer 8

Descemet’s Layer

Question 9

Function of the endothelium?

Answer 9

Essential in keeping the cornea clear as it pumps excess fluid out of the stroma. Without it’s pumping action, stroma would swell w/ water, become hazy, and ultimately opaque

Endothelium once gone, is lost forever

Question 10

Blood supply of the Cornea?

Answer 10

The cornea is avascular to keep it clear. Thus, it receives nutrients via diffusion from the tear fluids and the aqueous humor + the neutrophins from nerve fibers. It receives oxygen directly from the air.

blood vessels of the eyelid

Question 11

Innervations of the cornea?

Answer 11

70 to 80 large nerves + 7000 epithelial nerve endings
- Long and shor Ciliary Nerves
- Opthalmic branch of CN #5