FREAKING CONJ Flashcards
What are the three functions of the conj?
- Ensure smooth movement of the eyelid over the globe
- Help lubricate the eye by producing small amount of mucous and tears
- Keep microbes out of the eye
What kind of epithelium is the conjunctiva epithelium?
- non keratinized
- stratified squamous epithelium AND stratified columnar epithelium
The epithelial layer of the conj contains what cells and other structures?
- vessels, fibrous tissue, lymph channels
- goblet cells
- t and B cells and monocytes for immune response
What is present in the conj to help produce tears?
Accessory lacrimal glands (krause/wolfring)
What are the three segments on the conj?
- palpebral/tarsal conj
- bulbar conj
- conjunctival fornix
What does the palpebral conj line?
-lining of the eyelids
What does the bulbar conj line?
-converts the sclera
What is the conjunctival fornix?
-the cul de sac that connects palpebral and bulbar conjunctiva
Where are conjunctival stem cells?
They are scattered in the basal layer throughout the conj, but are more numerous in the fornix region
Name the fornices, their location, and their depth
- superior: under upper lid. 8-10mm deep
- Inferior: under lower lid. 8-10mm deep
- Lateral: extends posterior to the equator of the globe. 14mm deep
- medial: confined by the lacrimal apparatus. Shallow at 7mm deep
What is the deepest fornix?
Lateral! 14mm
What do the folds in the fornix allow for? Are they tight or loose?
- they allow for eye movement. They are pretty loose, so trauma or surgery can lose folds and make it tighter and less mobile
- they attach to the facial extensions of the levator, tarsal, and EOM
What happens at the mucocutaneous junction?
-the nonkeratinized squamous palpebral conj epithelium is continuous with the keratinized squamous epithelium of the epidermis of the eyelid
When is the bulbar conj not colorless?
When its blood vessels are engorged
Is the bulbar loose or tightly adhered?
-loose up to 3mm of the cornea (conjunctival limbus) where is tightly adheres to the tenon’s capsule and sclera
What is a sub-conjunctival hemorrhage?
Mild amount of blood trapped between bulbar conj and underlying episclera
Plicae Semilunaris: what is it? Where is it? What is it composed of? What is the function?
- crescent-shaped fold of the conj
- located at medial canthus
- epithelium is 8-10 cells thick and contains goblet cells
- stroma is vascularized with smooth muscle fibers and adipose tissue
- allows full lateral movement without stretching? Really just allergies
Caruncle: what is it? What kind of epithelium? Anything special about it?
- mound of tissue that overlies the medial angle of the plica semilunaris
- nonkeratinized epithelium with accessory lacrimal glands
- skin elements: hair follicles, sebaceous and sweat glands
- sebaceous glands are probs source of sleep in medial canthus
What is the blood supply for the palpebral conj?
-palpebral arcades of the lids anastomose with each other on either side of the tarsal plate
What is the blood supply to the fornices?
-palpebral arcades extend into the fornices of the lid
What is the blood supply of the bulbar conj?
-palpebral arcades branch and extend into the bulbar conj and anastomose with anterior conj arteries and anterior ciliary arteries
Where do the conjunctival veins drain?
Into the palpebral and ophthalmic veins
What provides sensory innervation for bulbar conj?
Long ciliary nerves
What provides sensory innervation to superior palpebral conj?
-frontal and lacrimal branches off V1
