The conjunctiva is a mucous membrane that lines the inner surface of the eyelids and covers the anterior portion of the eye. It has three parts - the marginal, tarsal, and orbital conjunctiva. The marginal conjunctiva extends from the eyelid margin to the subtarsal fold. The tarsal conjunctiva is firmly attached to the tarsal plate. The orbital conjunctiva lies loosely over underlying structures. Histologically, the conjunctiva has an epithelial layer, adenoid layer, and fibrous layer. The epithelial layers vary between regions from stratified squamous to columnar epithelium. The adenoid layer contains lymphocytes and the fibrous layer consists of collagen and elastic fibers with blood vessels and nerves

3.  IT is a translucent mucous membrane which lines the posterior surface of the
eyelids & anterior aspect of eyeball.
The normal conjunctiva is-
o pink
o Smooth
o Thin
o Transparent
There are normally large deep blood vesells that run vertically.

4. The conjunctiva helps lubricate the eye by producing mucus and tears, although a
smaller volume of tears than the lacrimal gland.
It also contributes to immune surveillance and helps to prevent the entrance of
microbes into the eye.

6.  It is richly vascular, extremely thin and strongly bounded to the tarsal plate.
 It is subdivided into 3 parts-
A. Marginal
B. Tarsal
C. orbital

7. o Extends from the lid margin to about 2 mm back of the lid upto the sulcus
subtarsalis.
o Actually a transitional zone between skin & the conjunctiva proper.
o Lacrimal puncta open in the marginal zone.

8. o Thin , transparent & highly vascular
o Firmly adherent to the whole tarsal plate in the upper lid and only to half width of
the tarsus in the lower lid.
o The tarsal glands are seen through it as yellow streaks.

9.  It lies loose between the tarsal plate & the fornix.
 Orbital margin of the upper eyelid is loose and lies over the muller’s muscle.

10. o It is transparent and lies loose over the underlying structures and thus can be
moved easily.
o It is separated from the anterior sclera by episcleral tissue & tenon’s capsule.
o The average thickness is 33 microns
o It is also known as ocular conjunctiva
o It is further of two types.- limbal, sclera

11. A 3mm ridge of bulbar conjunctiva around the cornea is called limbal conjunctiva.
Strongly adherent to sclero-corneal junction

12. COVERS the eyeball above the anterior sclera & hence known as scleral
conjunctiva.
Thin, transparent & loosely attached to underlying sclera
Separated from the sclera by episcleral vessels and tenon’s capsule.

13.  It is thin, transparent, continuous circular cui-de-sac
 It is broken only on the medial side by caruncle and the plica semilunaris.
 It joins the bulbar conjunctiva with the palpebral conjunctiva.
 It is further of four types-
1. Superior
2. Lateral
3. Medial
4. inferior

16. HISTOLOGY
OF
CONJUNCTIV

17.  Histologically cornea consists of 3 layers
1. Epithelium
2. Adenoid layer
3. Fibrous layer

18.  The layers of epithelial cells in the conjunctiva vary from region to region and its
different parts are
oMARGINAL CONJUNCTIVA:-
 have 5layers non-keratinised stratified squamous type of epithelium.
Superficial layer- squamous cells
Intermediate 3 layers- polyhedral cells.
Deepest layer- globlet cells.

19. oTARSAL CONJUNCTIVA-
Has 2 layers epithelium in the upper eyelid.
Superficial layer-cylindrical cells.
Deep layers- cubical cells
Lower tarsal conjunctiva is made of 3-4 layers of cells like the cubical, polygonal, elongated
wedge shaped and cone shaped cells.
oFORNIX & BULBAR CONJUCTIVA-
3 layered epithelium
Superficial layer-cylindrical cells
Middle layer- polyhedral cells
Deep layer- cuboidal cells

20. 8-10 LAYERS of stratified squamous epithelium
Most superficial 1-2 layers squamous cells.
Intermediate several layers-polygonal cells.
Basal layer- cylindrical or cubical cells.

21. a. Goblet cells
b. Melanocytes
c. Langerhans cells
d. Conjunctival associated lymphoid tissue.
e. Mucosal associated lymphoid tissue.

22. Also called as lymphoid layer
Consists of fine connective tissue reticulum in the meshes of which lie the
lymphocytes
Most developed in the fornices and ends at the subtarsal fold.
Develops after 2-3 months of life.

23. Consists of a meshwork of collagenous and elastic fibres.
Thicker than the adenoid layer
Except in the tarsal conjunctiva where it is very thin.
This layers consist vessels and nerves of the conjunctiva.
The adenoid layer & the fibrous layer are collectively called as substantia propia.