lab 5 eye histology

Question 1

The eye layers

Answer 1

3 basic ones: the outer cornea/sclera, the intermediate uveal layer and the inner retinal layer

Corneal scleral junction: limbus - the surface of the eye is covered by the conjuctiva-white

Uvea: highly vascular layer three layers: choroid (between the sclera and retina posteriorly, heavily pigmented), anteriorly the choroid turns into ciliary body and surrouds the lens held by suspensory ligament, iris is the third component of the uvea : divides anterior compartment into ant and post chamber

viterous body thick gel behind lens, and aqueus humor is infront of the lens

Question 2

Aqueous humor

Answer 2

secreted in post chamber by ciliary body and ciculated thru pupil to drain into canal at angle of the ant chamber canal of schlemm

Gives nutrients to lens and cornea

Question 3

vitreous body

Answer 3

has a canal which extends from optic nerve to post surface of lens aka the hyaloid canal

Question 4

retinal layer

Answer 4

photo sensitive, inner lining of post compartment, the ora serrata, behind the ciliary body

Question 5

visual axis

Answer 5

fovea, surrounded by yellow pigmented zone, macula lutea

optic nerve exits in sclera as the lamina cribrosa, the retina overlying is called optic disc devoid and blind spot

Question 6

tunics

Answer 6

the fibrous corneoscleral layer is comosed of the cornea and sclera

The vascular/pigmented layer, uveal layer composed of the iris, ciliary body, and choroid

The retina constitutes the neural layer

Question 7

cornea

Answer 7

major refractive structure of the eye, avascular/transparent structure, makes up 1/6th of the corneal scleral layer

has 5 layers: corneal epithelium (Strat. squamous non keratinized, about 5 cells thick, with lots of free endings), bowmans membrane (thick basement membrane), stroma/substantia propria (bulk of cornea, collagen), descemets membrane (a basement membrane), corneal epithelium (flattened cells that line the inner surface of cornea)

Question 8

iris

Answer 8

spincter pupillae and dialator

Question 9

lens

Answer 9

anterior lens cells and lens fibers are seen well

Lens capsule surrounds lens, and zonule fibes are thin wisps of pink fibers

Question 10

ciliary body

Answer 10

ciliary body: ciliary processes, at end its the ciliary muscles, allows for accomidation

recieve para symp innervation

Question 11

neural layer

Answer 11

retina is the photosensitive posterior part, the border of the non photo senstive anterior portion is called the ora serrata

Question 12

retinal layers exterior to interior

Answer 12

1. choroid and bruchs membrane , with open vascular layers, and between the choroid and first layer of the retina is a thin basement membrane is called bruchs membrane
2. Retinal pigment epithelium:simple cuboidal epithelium, absorb light and phagocytose vesicles
3. Photoreceptors (Rods and cones): highly elongated cells with a photoreceptor layer, outer limiting membrane, outer nuclear layer, outer plexiform layer (outer segments of the rods and cones are embedded in the RPE with many layers of light sensitive) (inner segments have the organelles of the cells)

Question 13

Photo receptor layers

Answer 13

1. rod and cone processes
2. outer limiting processes
3. outer nuclear layer
4. outer plexiform layer (almost featureless contains synaptic connections between photoreceptor cells and integrating neurons)
5. inner nuclear layer (of integrating neurons)
6. inner plexiform layer (of integrating neurons)
7. ganglion cell layer
8. afferent fiber layer axons going to disc
9. inner limiting membrane

Question 14

inter neurons

Answer 14

photo receptors synapse onto interneurons

Question 15

fovea

Answer 15

highest visual acquity almost exclusively cones