Orbit and Eye part 2

Created by jenbryant03 

Upgrade to
remove ads

gray's chapter 8 Ross histology chapter

where in the eye is the highest visual acuity

fovea centralis

eye development

optic vessels from evagination of forebrain-> contact surface ectoderm-> induction of lens placodes->lens vesicle
optic cup from optic vesicle->choroid fissure (pigmented layer of retina)
fissure allows hyaloid artery

the developing retina is part of

CNS

where is site of future retinal detachment in developing eye

intrretinal space

which artery becomes the central artery of the retina

hyaloid

what induces the formation of corneal epithelium

developing lens tells the overlying ectoderm

origin of most of the cornea

mesoderm

what forms from the loose mesenchyme around the eye primordium

inner choroid-contin with pia & arachnoid of optic nerve
outer scleral- contin w/dura of optic nerve

what layer forms the extraocular eye muscles

mesoderm

outermost layer of eye

fibrous coat
sclera
cornea

sclera

dense ct
bundes of collagen parallel to eye

cornea

transparent, avascular

middle layer of eye

vasular coat or uveal tract
choroid, ciliary body, iris

innermost layer of eye

retina

limbus cornea

area betw cornea and sclera
vascular

neuroretina

cns
10 layers

ora serrata

transition from 10 layer to 2 layered nonsensory retina

5 layers of cornea

corneal epithelium
Bowman's layer (basal lamina)
stroma (thick!)
Descemet's membrane
corneal endothelium (no bv)

nutrients to cornea come from

tear layer
aqueous humor

transition of myelinated to unmyelinated neurons in cornea

stroma->unmy as they cross bowman's layer

composition of cornea stroma

collagen lamellae wtih fibroblasts/ecm

what does the transparency of the cornes depend on

arrangement of collagen and ecm affinity for water
opaque without water

cornea endothelium permeable to

air/O2
uses 30% glucose

choroid

spongy, brownish
4 layers

4 layers of choroid

Bruch's membrane (lamina elastica)-5 layers
choriocapillaris-capillaries to nourish outer retina
vessel layer-larger vessels
epichoroid- near sclera

5 layers of Bruch's membrane

basal lamina of pigmented ep of retina
collagen
elastic
collagen
basal lamina of choroidal capillaries

what produces aqueous humor

ciliary processes of bodies

inner layer of ciliary process

nonpigmented
faces post chamber

outer layer of ciliary process

pigmented
faces stroma of ciliary body

2 surfaces of iris

ant- no epithelium
post- 2 layers of pigmented ep continuous with retina- contains melanocytes, myoepithelial cells (dilator pupillae)

fixed/dilated pupils

do not respond to light
unopp action of dilator pupillae(symp)
brainstem damage in edinger westfall nucleus

features of Horner's syndrome

ptosis- droop from denervated Muller's muscle
anhidrosis
miosis

innervation path of dilator pupillae

postgang symp from superior cervical ganglion- pregang in interomedial cell column of T1 spinal cord (uncrossed)
myoepithelial cells in indeterminant layer ant to pigmented layer

presbyopia

lens loses flexibility, can't thicken
farsightedness (older ppl)

3 parts of lens

capsule
subcapsular epithelium
lens substance

10 layers of neuroretina outside-in

1 pigmented epithelium
2 rods/cones
3 external limiting membrane (Muller cells)
4 external nuclear layer
5 external plexiform layer
6 internal nuclear (synapse Muller nucei)
7 internal plexiform
8 ganglion layer
9 optic nerve fiber layer
10 inner limiting membrane

which neuroretina layer can have astrocytes

9-optic nerve layer

functions of pigmented epithelium of retina

absorb light/prevent reflection
store/release Vit A
phago membrane from photoreceptor lamellae

what is indicated in retinitis pigmentosa

failure of phago of photoreceptor membrane, build up of debris

rods

more
all over neuroretina
low light
cylindrical outer segments-lamellae w/disc of rhodopsin, embedded in pigment epithelium, constantly being turned over
thin neck to inner, mito

what phagocytoses the old lamellae at rod tip

pigment epithelial cells

cones

fewer
most in fovea centralis
visual acuity and color
tapered outer segments- infoldings of plasma mem

what inhibits the migration of oligodendroglial cells in eye

lamina cribosa

bs to outer retina

pigmented ep and receptors supplied by choriocapillaries of choroid layer

bs to inner retina

central retinal artery

wet age related mac degeneration

10%
severe- most vision loss
0.2mill in US
sep photoreceptors from bs

dry age related mac degeneration

90%
1.8mil in us

drusen

accumulation of material between Bruch's membrane and pigmented epithelium
DRY ARMD
in wet, bv grow up and cause further sep

test for armd

amsler grid

detached retina

betw pigmented ep and photoreceptors
photo have no bs, die

papilledema

inc intracranial pressure cause optic disc/papilla to bulge into eye

anterior chamber of eye

cornea to lens
lateral border is trabecular meshwork (pectinate ligament) leading to canal of Sclemm

posterior chamber of eye

iris to lens
lateral by zonule/ciliary processes

open angle glaucoma

major cause of blindness
myopia and diabetes inc risk
angle of ant appears normal
blocked canal of Schlemm
gradual

closed angle glaucoma

rarer
ant angle blocked by iris
constricted pupil-angle is open
dilat pupil- angle closed
sudden emergency
ocular pain, blurred vision, hlos or rings around lights

optic cupping

inc intraocular pressure from glaucoma
pale optic disc
disc enlarged
retinal atrphy/neuronal death

vitreal body

transparent, jelly fills vitreous chamber
99%water
collagen, glycosaminoglycans
hyalocytes make coll and glycosamino
keeps retina in proper position

floaters

deposits in vitreous
prob vitreal proteins
benign
sudden app = serious disease

loss of vitreous humor

replace with saline to keep retina in place and maintain eyeball shape

vitrectomy

removal of cloudy/bloody vitreous

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set