Uvea Flashcards
the uvea contains 3 structures…..
- ciliary body
- iris
- choroid
the main function of the choroid is to…
provide nutrition to the retina
the main function of the ciliary body are…TRIPLE A
- accommodation
- aqueous humor formation
- absorption of light
the main function of the iris is to
control the retinal illumination and the image quality
uveal properties
- highly ____
- richly ____
- _____ specilization
- vascular
- innervated
- regional
the regions of the ciliary body are…
pars plana and pars plicata
post. region of the ciliary body that is continuous w/ the retina and choroid
pars plana
the junction btwn the ciliary body and retina
ora serrata
anterior, ridged and elevated portion region of the ciliary processes that produce aqueous from the blood supply
pars plicata
ciliary body structure
- forms ____ ring
- triangular ____mm wide
- firmly attached to _______
- extends to _____
- complete
- 6mm
- scleral spur
- ora serrata
the vessels in the pars plicata have a high _______ and are _____
internal pressure
fenestrated
the non-pigmented inner layer of the ciliary epithelium …
- produces ______
- continuous w/ the _____ retina
- continous w/ _______ epithelium of iris
- aqueous humor
- neural retina
- pigment
the pigemented outer layer..
- continuous w/ ____
- continuous w/ ______ muscle of iris
- RPE
2. dilator
the layers of the ciliary body are….(3)
- 2 layers of epithelium: pigmented/non
- stroma
- muscle
what kind of muscle is the ciliary body muscle
attached to _____
controls the shape of the _____
highly vascularized smooth muscle
scleral spur
lens
the ciliary muscle is densely _______
innervated.
a diffuse innervation system allows a single nerve to innervate many fibers
contraction of the ciliary muscle moves the ciliary body _______
- _____ relax
- ____ increases in power: accomodation
- no _____
anteriorly
zonules
lens
antagonist
no antagonist so why does the lens move back to the original position
because of the elastic membrane of the choroid which acts as a spring
parasympathetic innervation is done by CN ___ and _____
3
ciliary ganglion
sympathetic innervation is ____% of terminals and is done by the _______
1%
superior cervical ganglion
sensory innervatoin is done by CN ____ and the ant ______
5-opthalmic portion
ant. stroma possibly baroreceptor
- during development of the eye, the neural tube invaginates until it forms a _______ cup
- the outer layer of the cup is _____
- the inner layer is ______
- a double layered cup
- pigmented
- unpigmented (until it reaches the iris where it becomes pigmented)
the inner layer of the ciliary epithelium is _______
the outer layer is ________
transparent
highly pigmented
by the time the embryo is 4mm in length, the primary optic vesicle has moved ____ toward the neural tube
- lens ______ begins
- _________ collapses onto itself
- inner ________ becomes neural retina
- outer part becomes ______
outward
- lens induction
- optic vessel
- invagination
- RPE
embryonic invagination of the optic cup leads to the _______ of the photorecptor outer segment and the RPE
appositoin (apex to apex)
the invaginating inner wall gives rise to the ________ which includes the photoceptors, bipolar, ganglion, horizontal, and amacrine cells
neural retina
the obliterated space btwn the POS and the PE is a residuum of the ventricular cavity. this is a potential space called the ….
ocular ventricle
basement membrane of the RPE is the….
bruch’s membrane
the basement of the neural retina becomes the ….
internal limiting membrane
the inner limiting membrane is made by the…
muller cells and their feet
in a young eye, the ciliary epithelium:
unpigmented:
1. _____ and _____ interdigitations
2. ____ junctional complexes
pigmented:
_____ granules
- infolding and lateral
- apical
-melanin
infolding and later interdigitations are important for…
generating aqueous humor
apical junctional complexes hold_______ when under stress from muscles and zonules
cells together
in an older eye, the ciliary epithelium:
unpigmented:
1. ______ basal ends
2. ____ of basement membranes
3. _____ pull apart and the ILM protrudes
pigmented:
1. ________ basal ends
- irregular
- thickening
- cells
- irregular
the interdigitating surfaces of the pigmented and nonpig epithelium are joined together by ______ that form a _________ barrier to molec such as proteins
tight junctions
blood/aqueous barrier
what happens to the blood barrier w/ inflammation, trauma, and vasucalr disease
-aqueous then becomes _____
breakdown
-cloudy and flare is seen bc of large molec inside
the presence of gap junctions btwn the cells allows _______ of ions w/in the epithelial layers
free movement
in this iris, the tight junctions are found on the …
what type
vascular endothelial cells as the capillaries
-non-fenestrated impermeable type
aqueous humorformation is formed by:
- _____ of ions and molecules
- ______ of plasma in _____
- _________ of Na into ______ chamber by the non-pigmented ciliary epithelium
- diffusion
- ultrafiltration, stroma
- active secretion, posterior
is ultrafiltration active or passive?
passive bitch.
describes the bulk fucking flow of plasma across the fenestrated ciliary capillary endothelia into the ciliary stroma
secretion of aqueous humor:
- _______ diffusion and ______ of water and ions into the stroma
- ________ of Na into post. chamber depends on _______ exchange
- formation of _____ ions and _____ ions
- exchange
- _____ follows he ion gradient created by the ______ pump
- ______ follows ions
- passive, ultrafiltration
- ultrafiltration, Na/H
- H+, HCO3-
- bicarbonate, Na+/K+
- water
what enzyme provides the energy for the metabolic pump that transports Na into the post chamber by catalyzing the breakdown of ATP into ADP
Na+K+ ATPase
what catalyzes the rxn of the combo of carbondioxide into carbonic acid and its subsequent breakdown into H and bicarbonate
carbonic anhydrase
what enzyme affects production of cAMP
adenylate cyclase
adrenergic receptors affect smooth muscle tone and vascular tone in …(3 things)
- iris
- ciliary body
- endothelial linings of outflow pathways
the increased OUTFLOW facility is mediated by …
adenylate cyclase cAMP pathway
also…
PROBABLY, but just PROBABLY as a result of prostaglandin production -___-
waht reduce aqueous humor production through an adenylate cyclase cAMP pathway (inhibition of adenylate cyclase activity)
adrenergic alpha2 agonists
beta2 antagonists
cholinergic receptors are located in…
the ciliary body and iris
stimulation of cholinergic receptors cuases:
- ______ of the ciliary muscle and iris sphincter that may _____ outflow resistance
- _______, which reduces IOP
- _______ in aqueous humor formation
- contraction, reduce
- pilocarpine (parasympathomimetic)
- no significant role
aqueous humor is mainly made of…(3 thigns)
- electrolytes
- low molecular weight compounds
- some protein (very low-200x less than blood)
theres also a shit ton more shit in the aqueous…..
- ___ hormones
- _______ (carbonic anhydrase, lysozyme, cytokines)
- _______ (norepinephrine, dopamine)
- prosta….
- _____ acid (from GAG renewal in vitreous or ant segment
- sex
- enzymes
- catecholamines
- prostaglandins
- hyaluronic
why is the content different in plasma and aqueous?
bc of the tight junctions btwn non-pigmented ciliary epithelial cells that form a bloood/aqueous barrier
where are the source of metabolites in aqueous humor
ciliary processes (main) and also corneal endothelium, lens, and iris
iris structure contains…
- ____ limiting layer
- _____ epithelium
- _______ epithelium
- anterior
- stroma
- dilator epithelium
- pigment ep
what has the largest mass of smooth muscle (longitudinal fibers, radial fibers, circular fibers
ciliary muscle
contraction of the ciliary muscle leads to…
accommodation
the ciliary muscle attaches to _______, adjacent _______ tissue, or _______ sheets
scleral spur, cxt, corneal scleral
iris function
- _____ control
- ______ control for focus
- _____reduction
illumination
aperture
aberratoin
a meshwork of collagen fibers w/ many crypts and holes and is therefore very permeable
anterior limiting layer
the 3 ciliary muscles are
sphincter
dilator epithelium
radial contraction folds
what muscle has parasympathetic innervation w/ completely differentiated cells and it just smooth muscle
sphincter
what ciliary muscle does sympathetic innervation w/ only cells derived from neuroectoderm. incompletley differentiated. basal ends of these cells form the muscle process
dilator epithelium
what ciliary muscle gets deeper as the pupil gets smaller
radial contraction folds
what ciliary muscle gets deeper as the pupil gets wider
circular contraction folds
all the ciliary muscles secure very firmly to the epithelial layer at the….
pupillary margin
when the eyes are blue there is no….
melanin
what innervate the sphicter muscle? via what?
post ganglionic parasympathetic fibers from CN3 via short ciliary nerves
-constriction hell yeah
what innervates the dilator muscle of the iris? via what?
sympathetic fibers via long ciliary nerves
-dilation bitches
choroid function: 1. 2. \_\_\_\_ product removal 3. passage of \_\_\_\_\_ and \_\_\_\_\_ 4. \_\_\_\_\_ of stray light 5.
- nutrition
- waste
- nerves and vessels
- absorption
- emmetropization
the suprachoroid:
- lines the ____ and is very thin
- ______ contain pigment granules
- sclera
2. melanocytes
in hyperopic defocus there is a ___ choroid and ______ growth
thin, increased
in myopic defocs, there is a ____ chroid and ____ growth
thick, decreased
in the vascular layer of the choroid
- among the _____ capillaries in the body
- _____ permeable
- blood vessels maintain ________ pressure to resist IOP
- largest
- highly
- high
what are the 3 parts of the anatomy of the choriod
- suprachoroid
- vascular layer
- bruch’s membrane
blood supply to the choroid
- long posterior ciliary-how many?
- short post ciliary-how many?
- choriocapillaries
- ant ciliary arteries-how many?
- how many vortex veins?
- 2
- 8-20
- 7
- 4
long and short ciliary nerves travel ______ and supply the ________.
-they also carry _____ nerve supply
anteriorly, choroidal vasculature
-sympathetic
the short ciliary nerves also carry the ______ nerve supply from CN 3
parasympathetic
parasympathetic innervation of the choroid is from the …..
pterygopalatine ganglion
the post-ganglionic fibers are predominantly _____
cholinergic
sympathetic innervation arises from the….
superior cervical ganglion
innervation of the ______ restricts the blood flow in the choroid
sympathetic
what innervation increases blood flow in the choroid
parasympathetic
stimulation of sensory fibers from the trigeminal nerve elicits _____
vasodilation
from the nutritional standpoint, the retinal circulation only supplies the …
inner half of the retina
the choroid supplies the necessary metabolites to the….
posterior half of the retina
- large choroidal blood vessels fill the …….
- progressively smaller vessels are closer to the ______ forming the choriocapillaris
- choroidal layer
- retina
what decreases retinal illumination, reduces aberrations, and increases depth of focus
pupil constiction
eye accommodates
iris constricts
outflow increases
what contracts to allow these things to happen
ciliary muscle
what does the unpigmented layer of the ciliary epithelium make?
aqueous humor
where does the aqueous humor drain into
- from there, where can it drain into the venous system? (2 things)
- and then eventually it leaves the eye via….
trabecular meshwork
- schlemm’s canal via vacuoles or through the uveoscleral outflow
- VORTEXVEINSMEOW
chicks are weird, the choroid will adjust to its thickness to partially compensate for the defocus.
- if the img is focused in front of the retina the chroid layer willl……
- if the img is focused behind the photoreceptors then the choroid layer…
thickens to bring the retina closer to the focal plane
-thins, again brining the img closwer to the focal plane
