eye

1) fibrous layer- corneosclera 2) vascular layer- has choroid and cilary body, Iris 3) retina- neural and retinal pigment epithelium

non photosensitive region of the retina that lies under the iris and cilary body

anterior is - -anterior and posterior chambers plus all structures at the front of the eye posterior is- vitreous layer

supplies nutrition tx of metabolic waste avascular because don’t want anything getting in the way of light rays entering

-lots of blood vessel

-lens and the cornea = rely on the aqueous layer for nutrition

vascular layer of the retina

• collagen makes it gelatinous - helps keep the retina up on the vascular layer of the choroid

• part of the corneoscleral coat • anterior 1/6 of eye • provides 2/3 of the refractive power

1) corneal epithelium 2) bowman’s membrane 3) corneal stroma 4) Descemet’s membrane 5) Corneal endothelium

• continuation of the conjunctiva • stratified squamous • attached via desmosomes • lots of mitosis for repair • apex of cells have microvilla that help retain tears secreated- prevents corneal drying • Have FERRITIN to protect DNA from damage to UV light since melanin is absent • innervated by ophthalmic division of 5 -very sensitive

protect DNA from damage in the cornial epithelium since it does not have melanin

• second layer of the cornea (basement membrane) • no regeneration!!! • acellular • terminates at the cornealscleral limbus (where cornea changes over to sclera) • bowman is a tough guy!!!- helps with STRENGTH and STABILITY of the cornea and acts as a barrier to prevent spread of infections to the rest of the eye • if damaged can form an opaque scar which can impair vision (like DAD)

• third layer of the cornea • gives 90% of corneal thickness • transparent based on collagen arrangement in lamellae -right angles • Collagen and V and proteoglycans make sure the correct spacing occurs • disruption of the collagen fibers- make cornea look opaque

• Fourth layer of the cornea • second basement membrane and basement of the corneal Endothelium • Descemet is one resilient little bitch!- • regenerates after injury and thickens w/ age • interwoven meshwork of fibers and pores • MAINTAINS THE CURVATURE OF THE CORNEA VIA CONNECTIONS WITH SCLERA AND CILIARY MUSCLE- pectinate ligament

• faces ant. chamber of the eyeball • simple squamous joined by ZONA OCCLUDENS (TIGHT JUNCTIONS) and desmosomes • very little proliferation and thus little repair • injury =corneal opacity • RESPONSIBLE FOR VIRTUALLY ALL METABOLIC CHANGES OF THE CORNEA • lots of channels that allow for passage of nutrients fluids

• connect the sclera with the desemet’s membrane and allows desemet’s to maintain curvature of the cornea

• made of collagen and elastic fibers • maintains shape of the eyeball • tenon’s capsule- the outer layer of the sclera that is pierced by ocular muscles • sclera pierced by the optic nerve, vessels and blood vessels

• where the stem cells for the corneal epithelium are • where the sclera and cornea meet • -WHERE THE IRIDOCHORNEAL (cornea/iris) ANGLE IS underneath the corneal endothelium– how aqueous humor gets into the VENOUS system (constant)-canal of schlem

how the aqueous humor gets into the venous system (how it’s drained from the eye) located at the corneal scleral limbus (more specifically at the Iridochorneal angle)

• the vascular coat of the eye (perimeter) • contains the iris and ciliary body -from anterior segment • choroid from posterior segment

• separates anterior and posterior chambers of the anterior segment of the eye • color part of the eye • middle is the pupil • contractile diaphragm in front of the lens

-darkly pigmented to prevent glare

contractile diaphragm of iris- sympathetically controlled