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Conjunctiva, lacrimal system, cornea

Conjunctival Epithelium

continuous with skin of eyelid and with the cornea; 3-4 layers thick on lower, 2-3 on upper; stratified columnar near lids, squamous near limbus; goblet cells and crypts of Henle

Crypts of Henle

invaginations in conjunctival epithelium where things get stuck

Submucosal Conjunctival Layer

thicker in orbital than in tarsal; loose, vascularized CT; lymphoid and fibrous layers

Lymphoid layer of Submucosal Conj.

immunologically active IgA and has connective tissue components

Fibrous layer of Submucosal Conj.

blood vessels, nerves, collagen, accessory lacrimal glands

Palpebral Conjunctiva

covers inside of eyelids; connected at fornix to KPS and EOMS providing coordination of movement

Bulbar Conjunctiva

covers the sclera, loosely adherent to underlying tissue, more tightly near cornea, merges with Tenon's Capsule

Tenons Capsule

space which the globe moves in; protects the globe, attaches to orbital connective tissue

Fornix

where bulbar and palpebral conj. merge, lateral fornix is deepest, superior and inferior but NO medial

Lympathics

superficial and deep in the submucosa, drain into eyelids

Inn. of Bulbar Conj

long ciliary nerve

Inn. of Superior Palp. Conj

frontal and lacrimal n.

Inn. of Inferior Palp. Conj

lacrimal, infraorbital n.

Functions of Lacrimal System

tear drainage, movement and creation

Punctum

hole where tears drain

Canaliculi

tube coming from punctum; inferior and superior join together

Nasolacrimal Sac

common canaliculus drains

Nasolacrimal Duct

in maxillary bone, where sac drains, ends in inferior meatus

Valve of Hasner

at inferior meatus, keeps stuff from nose from getting into lacrimal system

lacrimal gland

located in fossa of same name, temporal and superior to the eye, sits on LPS and LR; orbital and palpebral divisions, ducts exit thru palpebral lobe

acini

lobes and accessory glands forming an irregular arrangement of secretory cells around the lumen, connected by ducts that drain into fornix

Lipid Layer of tears

waxy esters, cholesterols, FFAs made by Meibomian glands; keeps aqueous from evaporating and lubricates eyelid

Mucous layer

made by goblet cells, adheres tears to corneal surface, absorbed by glycocalyx

Aqueous layer

made by lacrimal gland; contains a lot of organic substance which forms the "crustyness"

Main functions of the Cornea

transmit light into retina and aid in focus 45 D of eye power; protects against infection; maintains pressures and balances of chambers

Cornea Epithelium

outermost layer, has 3 layers, lots of nerves, very sensitive to injury

Surface epithelium

2 layers thick, short, fat, non-keratinized squamous cells with flat nuclei and not many organelles; tight junctions make things go THRU cells instead of between; help tear movement

Wing Cell layer

convex anterior surface, concave posterior; joined by desmosomes, gap junctions and macula occludens

Basal layer

single layer of columnar cells; secrete basement membrane; sight of mitosis for cornea

Bowman's layer

very thing, dense fibrous sheet of collagen fibers in mucoproteins; NO CELLS, does not regenerate

Stroma

90% of cornea, strong, organized into lamellae of collagen fibrils with keratocytes in between layers; also has WBCs, PMNs, macrophages, nerves, ground substance

Ground substance of stroma

fills in spaces, made up of proteins and collagen that bind to water to keep consistent spacing; Keratin Sulfate and Chondroitin

Descemet's Membrane

anterior: collagen; posterior: regenerated thruout life, elastic properties; resistant to trauma but will roll up into anterior chamber if cut

Hassall-Henle Bodies

patho. dome shaped protrusions into anterior chamber coming from descemet's membrane; endothelium thins over them

Corneal Endothelium

basal part is more superior; single layer, maintains water balance by ion pumps; sits near ant. chamber; mosaic;

Nerves of the Cornea

long posterior ciliary and short posterior ciliary, a lot of free nerve endings in epi.

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