conjunctiva Flashcards
1
Q
where is the conjunctiva?
A
- conjunctiva is a thin transparent mucous membrane
- the membrane is continuous and lines three parts of the eye:
> palpebral conjunctiva - under surface of top & bottom eyelids
> bulbar conjunctiva - surface of eye, covering sclera
> conjunctiva fornices - junction between palpebral and bulbar conjunctivas
2
Q
palpebral conjunctiva
A
- lies the under surface of top & bottom eyelids
- subdivided into three portions
> marginal - transitional zone between eyelid & conjunctiva proper
> tarsal - posterior to tarsal plates of eyelid
> orbital - covers between the tarsal plate & fornix
3
Q
tarsal conjunctiva (palpebral conjunctiva)
A
- Thin and highly vascular, thus inner surface or eyelid appears pinkish red
- Upper eyelid: fully adherent to the whole tarsal plate at upper eyelid
- Lower evelid: onlv uoper portion or tarsal plates adherent
- Underlying tarsal glands are visible through transparent tarsal coniunctiva as vertical parallel streaks
4
Q
conjunctival epithelium
A
- Commences at orifices of tarsal glands
> Become extremely thin behind tarsal plate
> Increase in layers at limbus, conjunctival epithelium continuous with the corneal epithelium
> Continuous with epidermis of skin of eyelid at the edge of marginal conjunctiva - Consists of non-keratinised epithelium and goblet cells
- Goblet cells
> Zero goblet cells at limbus and marginal conjunctiva
> reach a maximum amount at conjunctival fornix
> Secretes mucin layer of the tear film
5
Q
conjunctival blood supply
A
ophthalmic artery
6
Q
conjunctival nerve supply
A
trigeminal nerve (CN V)