Aqueos Humor Flashcards
Why do we need the aqueous humor?
gives eyeball its shape, nutrients, gives refraction, shock absorber of the eye. Nourishment to cornea and lens.
Muscles are still acting so it would appear as a square structure if aqueous wasn’t there.
what is the refraction of aqueous humor?
1.3332
is the aqueos humor avascular?
yes
Depend upon a constant turnover of the surrounding aqueous to deliver nutrients
wash out metabolic waste products.
True or False/
True
Name the parts of the ciliary body.
Muscle
Vessels
Epithelia lining ciliary processes
Autonomic nerve terminals
Ciliary body is one of the 3 parts of what part of the eye?
uveal
longitudinal fibers connect what?
ciliary body to limbus
circular fibers connect….
anterior and inner portions of ciliary body.
radial fibers connect….
longitudinal and circular fibers.
what are the parts of the ciliary body muscles?
longitudinal fibers, radial fibers, and circular fibers
what are the parts of the ciliary body vessels?
1) Episcleral circle
2) Intramuscular circle
3) Major Arterial circle (paralimbal branches of LPCA
Lies near the iris root
Primary supply of iris and ciliary processes
4) cilliary process.
Ciliary process is supplied by what two branches of the arterial circle?
Anterior ciliary process arteriole
Posterior ciliary process arteriole
Ciliary process is the functional unit responsible for production of aqueous humor secretion. True or False
True
cilliary processes are made up of what?
capillaries, epithelium, stroma
where are the capillaries located in the cilliary processes?
center of each processes.
How many layers of epithelium are around the stroma?What are the names?
Two.
Pigmented and Non-pigmented epithelium.
what nutrients does the aqueous fluid have?
Source of antioxidants for the corneal endothelium and the lens
Carries oxygen similar to the interstitial fluid
Aqueous Humor has a HUGE SOURCE OF VITAMIN C. TRUE OR FALSE.
TRUE
Why is aqueous humor high in vitamin C? Do we want proteins in aqueous humor?
No we do not want proteins in aqueous humor. this is why its kept out. You want to prevent oxidative damage from light rays and waste products in eyes. You want to protect the proteins in lens. When it starts to degenerate it gets opaque. With production of blue light comes free radicals, which attacks tissues. Antioxidants prevents this from happening.
Does aqueous humor have oxygen? yes or no
No
absence of proteins and lipids in aqueous humor enhances light transmission. True or False.
True.
aqueous humor secreted by what?
ciliary epithelium or the ciliary processes
Where does the aqueous humor enter? Where does it also flow in other parts of eye?
the posterior part of the anterior chamber.
Its also flows around crystalline lens and through pupil anterior chamber.
what does aqueous humor secrete, ultra-filtrate, and diffuse?
1) Diffusion-lipid soluble substances
2) Ultrafiltration-Water and water-soluble substances
3) Secretion- larger size substances or greater charge (80-90% aqueous humor formation)
IOP is NOT a function of removal and production. T or F
FALSE
Typically, Aqueous humor production is greatest when?
when is it the least?
most in the morning 8am-12pm
least at night 12am-6am.
If a person works at night, when can you expect the amount of aqueous humor produced to be the most?
during the night.
the least during the day.
Inhibition of Na, K-ATPase or carbonic anhydrase increases or decreases aqueous production?- glaucoma management!
decreases
which one has tighter junctions pigmented or nonpigmented epithelium?
pigmented
what two components are involved in the formation of aqueous humor?
Na+ K+ ATPase and carbonic anhydrase
Describe the process of aqueous humor formation.
Active process mediated by the transport of certain ions and substances against the concentration gradient
Two enzymes Na, K-ATPase, and carbonic anhydrase
Na, K-ATPase is predominantly bound to plasma membrane of non-pigmented epithelium
Enzyme helps push the Na+ ions into posterior chamber to which water follows!
The formation of aqueous humor is a passive or active process?
Active process
Na+ K+ ATPase binds where?
plasma membrane of non-pigmented epithelium
Sodium ions are pushed where during the process of making aqueous humor?
posterior part of the anterior chamber, where water flows.
what can be used to decrease the amount of aqueous humor production?
carbonic anhydrase inhibitor
The aqueous humor has how many routes to leave? Name these routes.
two routes.
trabecular meshwork route
uveal scleral meshwork route
which route is more commonly used for aqueous humor to leave?
trabecular meshwork route (70%-95%) used more.
uveal scleral meshwork (5-30%)
Both total and trabecular outflow decline with age (leads pressure to go up). True or False
True
Describe the trabecular meshwork outflow of aqueous humor.
Through the trabecular meshwork
Trabecular or Conventional route
TM—>Inner wall of schlemm’s canal—>lumen—>Collector channels–> aqueous veins –> episcleral venous circulation
Resistance to outflow must be high if pressure if high. T or F
True
Aqueous Humor process was once thought to be inactive. T or F
True
Describe uvealscleral outflow route of aqueous humor. The unconventional posterior route.
Across iris root—>uveal meshwork—> the anterior face of cilary muscle—>connective tissue—> between the muscle bundles—>suprachoriodal space—> sclera
The blood aqueous barrier in aqueous humor describes the selective permeability of the aqueous humor. True or False How?
True
Pigmented and non pigmented epithelium are bound together by what?
tight junctions
Capillaries of the ciliary processes and the choroid are not fenestrated. True or False
False
Non pigmented and pigmented epithelium provide a barrier in the blood aqueous barrier of aqueous humor for what size substances?
intermediate and High molecular weight substances
The endothelia of the inner wall of Schlemm’s canal are similarly joined and prevent the movement of fluid and solutes from the Canal of Schlemm into the trabecular meshwork and anterior chamber.
True or False
True
Iris and retina possess a similar epithelium between their vasculature and the ocular fluids, they have fenestrated capillaries that are not permeable.
True or False
False. They have nonfenestrated capillaries that are not permeable.
Blood flow filtrates to create aqueous humor. T or F
True
As aqueous outflow and inflow increase, what should happen to IOP? increase or decrease
increase
As plasma components increase, what happens to IOP?
increase
As IOP increases during breakdown of blood aqueous barrier, aqueous inflow by ultrafiltration is suppressed, slowing down the rise in IOP. What is this called?
pseudofacility
increase in pseudofacility increase IOP. TRUE OR FALSE
FALSE. IT DECREASES IOP!!!!
Inflammatory response reduces the rate of active secretion of aqueous humor. T or F
True. Possibly by interfering with active transport mechanisms.
trauma, inflammation or disease can breakdown blood-aqueous barrier and in turn increase IOP. T or F
True
