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Ocular Anatomy 2
Conjunctiva, lacrimal system, cornea
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
covers inside of eyelids; connected at fornix to KPS and EOMS providing coordination of movement
covers the sclera, loosely adherent to underlying tissue, more tightly near cornea, merges with Tenon's Capsule
space which the globe moves in; protects the globe, attaches to orbital connective tissue
where bulbar and palpebral conj. merge, lateral fornix is deepest, superior and inferior but NO medial
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
hole where tears drain
tube coming from punctum; inferior and superior join together
common canaliculus drains
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
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
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
made by goblet cells, adheres tears to corneal surface, absorbed by glycocalyx
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
outermost layer, has 3 layers, lots of nerves, very sensitive to injury
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
single layer of columnar cells; secrete basement membrane; sight of mitosis for cornea
very thing, dense fibrous sheet of collagen fibers in mucoproteins; NO CELLS, does not regenerate
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
anterior: collagen; posterior: regenerated thruout life, elastic properties; resistant to trauma but will roll up into anterior chamber if cut
patho. dome shaped protrusions into anterior chamber coming from descemet's membrane; endothelium thins over them
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.