special senses

3 layers of the eye

fibrous external, vascular layer, inner

Fibrous external layer has?

sclera and cornea

Sclera is a __ _ tissue designed for? what is contained?

dense CT, protection and muscle insertion, type I collagen, fibroblasts, ground substance

3 functions of cornea

protection and support: collagen fibrils type I

helps focus light

enables light to enter (transparant)

how does corena focus light

what endothelium?

it is curved. simple squamous on bototm, stratified on top (epithelim)

Cornea epithelium: keratnized or not> how many layers? shape and feature?

non keratinized, 5 or 6, smooth or flat (transparancy), bowman’s membrane: thick basmeent membrane

The stroma is composed of

• uniform layers of ?

  • This does what and makes it what

• what blood suplly

• what cell

parallel fibrils, minimizes light scattering, transparanet, avascular, keratocytes

where do cells in cornea get nutirents (3)

oxygen from air, aqueous humor underneath, tears on top

The __ is important for maintaining transparaency with aquaous humor and stroma. how?

water pumped into humor, keeps it transparaent

What produces aqeuous humor, where?

ciliary process in ciliary body

How does aquous humor exit eye

schlemms canal (scleral venous sinus)

trabecular meshwork (holes of endothelium and CT)

Another function of the ciliary body is to ?

keep lens in place: suspensory ligaments

Near and far vision is controlled by the?

ciliary body/muscle

near vision is: muscle contract or relax? ligament contract or relax?

muscle contract, ligament relaxes

Two functions of iris and what acheives it>

control size of pupil: smooth muscle/contractile cells

prevent light from entering fissure: pigmented (melanin absorbs light)

2 muscles taht control dilation/constriction of pupil

dilator pupillae (myoepithelial cells) and sphincter pupilale (smooth muscle)

lens capsule: CT type IV

lens epithelium: simple cuboidal

starting at lens capsule: differentiation:

differentating fibers, elongate lose nucleus, gain cyrstallins, mature lens

choroid is?

CT with melanocytes and blood supply for retina

retina has two layers:

retinal pigemented epithelium (melanin), neural retina

cell types in neural retina

rods, cones, bipolar neurons, gnaglion cells, axons to optic nerve

What helps limit the uncontrolled reflection of light within eye

melanin