embedded in tarsal plate

sebaceous glands that contirbute to tear film

stratified columnar to squamous with goblet cells

lined by conjunctival epithelium

cartilaginous core

opaque in dogs and cats, clear in reptile and amphibian

goblet cells in the conjunctival epithelium

meibomian glands

lacrimal glands

7

2 oblique (dorsal/ventral)

4 rectus (dorsal ventral medial lateral)

retractor bulbi!

fibrous tunic

vascular tunic

nervous tunic

anterior: cornea

posterior:sclera

anterior: iris and ciliary body

posterior: choroid

epithelium

stroma

endothelium

normally non keratinizing (could keratinize if dried out?)

non pigmented

sits on basement membrane

scattered fibroblast keratocytes (not keratinocytes!!)

well organised collagen

white footballs

no blood vessels normally (injury)

highest concentration of nerves in the body - invisible w routine stain

simple squamous epithelium

basement membrane: Descemets

may not be attached after processing for slides

connective tissue on posterior eye

contains nerves and vessels

birds have cartilage or bone

empty space surrounded by iris

shape can vary by species

fibroblasts

collagen

lymphatics

blood vessels

nerves

epithelium

melanocytes

muscles

anterior surface or iris and within the stroma

absent in blue eyes

cirfumferentially around the pupil margins only

in mid stroma

present throughout the iris

in deep stroma

behind the iris

begins at the base of the iris and ends at the beginning of the retina

contains ciliary processes and ciliary muscle

zonule fibers

lined by 2 layers of epithelium: inner non pigmented and outer pigmented (remember inner is more superficial and outer is deeper bc its on the posterior iris)

make the aqueaous humor

smooth muscle in mammals, skeletal in non mammals

lots of pigment in brown eyes (none in blue)

connect the ciliary body to the lens

ciliary muscle contracts and pulls on fibers to change the shape of the lens: focus light on different parts of the retina

held in place by zonule fibers

avascular, nourished by the aqueous humor

transparent (normally)

thick and gets thicker w age (nuclear sclerosis)

lens epithelial cells underneath

migrate and elongate to form lens fibers and the bow shape of the lens

lose nuclei as migrate centrally

well organised and packed together

help with transparency in teh lens

imperfections and discoloration result in cataracts

space bw the cornea and in front of the iris leaflets

contains aqueous humor produced by ciliary body

space between the iris leaflets in front of the front half of the lens

contains aqueous humor

formed by iris and cornea

pectinate ligaments

drain aqueous humor out of eye

ciliary process

posterior chamber

anterior chamber

pectinate ligaments

trabecular meshwork

scleral plexus

venous system

obstruction of aqueous outflow resulting in increased intraocular pressure

increased IOP is almost never due to inc production of aqueous humor

posterior compartment (NOT posterior CHAMBER!!)

filled with vitreous humor

gelatinous

transparent

hold lens and retina in place

Ganglion Cell Layer (inner most nuclear layer)

Inner Nuclear Layer

Outer Nuclear Layer (contains bodies of rods and cones)

FALSE

ganglion layer is more inner

not always pigmented in animals...

cuboidal epithelium

eats photoreceptor outer segments to help with normal cell turnover

varies by species:

on top of retina

within retina

not present

always in inner retina - the outer portion is fed by the choroid!

surrounded by meninges

arteries that supply retina enter the globe here too

choroid

blood vessels and supportive connective tissue

pigmented in most animals

nourishes outer portion of retina

layer of reflective tissue in dorsal choroid

bounces light back to stimulate the retina twice

not present in all species

RPE over it is not pigmented...