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Flashcards in Aqueous Humor Dynamics Deck (73)
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1

how many diopters does the aqueous humor contribute to refraction

1.33 D

2

why does the eye need aqueous humor

shape, optical properties, shock absorber, and carries antioxidants, oxygen and nourishment to cornea and lens

3

what are the avascular structures of the anterior segment

lens and cornea

4

why does the aqueous humor need constant turnover

to deliver nutrients and wash out metabolic waste products

5

what are 4 parts to the ciliary body

muscle, vessels, epithelia lining ciliary processes and autonomic nerve terminals

6

what are the 3 muscles of the ciliary body

longitudinal, circular, and radial

7

what are the 3 vessel circles of the ciliary body

episcleral circle, intramuscular circle, and MAC

8

what is the primary blood supply to the iris and ciliary processes

Major arterial circle

9

what are the 2 branches of the MAC that supply the ciliary processes

anterior and posterior ciliary process arterioles

10

what is the functional unit responsible for production of aqueous humor secretion

the ciliary process

11

what 3 things make up the ciliary process

capillaries, stroma, and epithelia

12

what occupies the center of each ciliary process

capillaries

13

why does aqueous humor carefully control filtrate of blood

otherwise certain things will enter the anterior chamber and inhibit light from reaching the retina or scattering light

14

what component is in higher concentration in aqueous humor compared to blood

ascorbate (vitamin C)

15

why does aqueous humor have a high concentration of vitamin C

it is an antioxidant

16

what components are in blood that you don't want to have present in aqueous humor

proteins, lipids, cholesterol, hemaglobin

17

what is the main/maximum source of aqueous humor formation

secretion (80-90%)

18

when is aqueous humor production the lowest

at nighttime

19

when is aqueous humor production the highest

in the mornings

20

is aqueous formation an active or passive process

an active process, requires energy

21

what mediates the active process of aqueous formation

the transport of certain ions and substances against the concentration gradient

22

what are the 2 enzymes in the aqueous formation process

Na, K-ATPase and carbonic anhydrase

23

where is Na, K-ATPase predominantly bound

to plasma membrane of non-pigmented epithelium

24

which ions are pushed into the anterior chamber that cause water to follow

sodium ions

25

how would you stop water from entering the anterior chamber and decrease aqueous production

use a carbonic anhydrase inhibitor

26

what do bicarbonate and hydrogen ions form

carbonic acid (H2CO3)

27

what acts on carbonic acid to produce CO2 and H2O

carbonic anhydrase

28

which part of the anterior chamber, anterior or posterior, has a higher pressure

the posterior has a higher pressure

29

what causes the pressure gradient to move the aqueous humor to the anterior chamber

having a higher pressure in the posterior chamber helps move the fluid into the anterior chamber through the pupil

30

why does the vitreous act as a barrier for aqueous humor

the GAGs in the vitreous give it a gel consistency and help push the aqueous into the anterior chamber