Wednesday, July 23, 2008

- Histology of the cornea.

Histological structure :- is Composed of 5 Layers:-



1- Epithelium:-

  • Active mitosis → regeneration within 6- 24 hrs.
  • Continue with conjunctiva.
2-Bowman's membrane:-

  • Acellular Clear membrane lie under the epithelium.
  • Ends abruptly at the limbus. (i.e. end in folded manner)
  • Is considered as modified lamella of stroma.
  • If destroyed cannot regenerate.
3-Stroma:-
  • Represent 90% of corneal thickness .
  • Formed of collagen fibrils (Type 1) which has special arrangement which run parallel to each other and parallel to the surface of the cornea making the cornea transparent, unlike sclera in which arrangement is not done in specific way so appear opaque.
  • Collagen fibrils lie in mucoid matrix Scattered keratocytes lie between lamellae and are stellate in shape.

4-Descemet's membrane:-

  • An elastic membrane which lie ( ) Endothelium and stroma.
  • It is resistant to pathology and regenerate easily. 
  • This layer is continuous with material of the pectinate ligament or trabecular meshwork of the iris.
5-Endothelium:-
Single layer of flat hexagonal cells with No mitosis.

- Pumps water out → prevent corneal edema → prevent corneal opacification.



(By light microscope)
So Cornea formed of :-

  • Epithelium resting on B.M
  • Endothelium resting on D.M
  • stroma in between

5 comments:

  1. very niceeeeeeeeeee thx alot

    ReplyDelete
  2. type 2 collagen in substantia propria.

    ReplyDelete
  3. Realy helpful.tnx

    ReplyDelete

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