Conjunctiva

anatomy and physiology of conjunctiva

1. CONJUNCTIVA – ANATOMY AND PHYSIOLOGY -AARTHY.M.R.S.

2. CONJUNCTIVA: It is a thin , semi transparent mucous membrane that covers the inner surface of the eyelid and the white part of the eyeball (SCLERA)

3. PARTS OF CONJUNCTIVA: PALPEBRAL CONJUNCTIVA FORNICEAL CONJUNCTIVA BULBAR CONJUNCTIVA

4. PALPEBRAL CONJUNCTIVA: Covering the lids Firmly adherent Highly vascular Extremely thin Strongly bound to the tarsal plate

5. FORNICEAL CONJUNCTIVA: Covering the lids Thrown into folds Transitional region between palpebral and bulbar conjunvctiva Superior fornix - 10 mm from limbus Inferior fornix - 8 mm from limbus Lateral fornix – 14 mm from limbus Medially absent

6. BULBAR CONJUNCTIVA: Covering the eyeball Thin,translucent and loosely attached to the underlying sclera by TENON’S CAPSULE Conjunctival limbus 1mm anterior to corneal limbus

7. EPITHELIUM OF CONJUNCTIVA: The inner surface of the eyelids and the outer surface of the eyeball are lined by STRATIFIED COLUMNAR EPITHELIUM containg goblet cell which secretes mucus

8. At limbus,change into stratified squamous non-keratinized epithelium At lid margin,change into stratified squamous keratinized epithelium Presence of accessory lacrimal glands The epithelial layer contains blood vessels,Fibrous tissue and lymphatic channel

9. BLOOD SUPPLY: Anterior conjunctival arteries derived from the Ant.ciliary arteries Posterior conjunctival arteries derived from the Arterial arcade of lids which is formed by palpebral Branches of nasal and lacrimal arteries of lids ARTERIAL SUPPLY: VENOUS DRAINAGE: Palpebral and ophthalmic veins

10. NERVE SUPPLY: BULBAR CONJUNCTIVA: long ciliary nerve Naso ciliary nerve Ophthalmic division of trigeminal nerve SUP.PALPEBRAL AND FORNICEAL CONJUNCTIVA: Frontal and lacrimal branches of ophthalmic division of trigeminal nerve

11. INFERIOR PALPEBRAL AND FORNICEAL CONJUNCTIVA: Laterally- lacrimal branches of ophthalmic division of trigeminal nerve Medially- infraorbital nerve maxillary division of trigeminal nerve SYMPATHETIC: Superior cervical sympatics to blood vessels

12. LYMPHATIC DRAINAGE: Lymph vessels are arranged as a deep and a superficial plexes in submucosa

13. PHYSIOLOGY OF CONJUNCTIVA: Smooth surface Secretes mucin and aqueous component of tear flim Highly vascular:supplies nutrition to the peripheral cornea Aqueous veins drain from ant.chamber for the maintanence of IOP Helps to prevent the entry of microbes into the eye