Aqueous And Vitreous Humo Flashcards

1
Q

Optically clear, slightly alkaline liquid that occupies the anteiror and posterior chambers of the eye

A

Aqueous humor

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2
Q

What does aqueous humor have less of than blood plasma

A

Protein and glucose

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3
Q

What does aqueous humor contain more of than blood plasma

A

Lactic acid and ascorbic acid

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4
Q

What does the aqueous humor provide

A

Necessary metabolites, primarily oxygen and glucose, to the avascular cornea and lens.

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5
Q

Where is aqueous humor produced

A

Pars plicata

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6
Q

Where is the aqueous humor secreted

A

Posterior chamber through the epithelium covering the ciliary process

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7
Q

What is the function of ascorbic acid

A

Reducing and antioxidant agent that functions in fighting bacterial infection, detoxifying reactions, and in the formation of collagen in fibrous tissue, teeth, bones, CT, skin, and caps

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8
Q

What is aqueous humor filtered from

A

Blood

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9
Q

What is the aqueous humor secreted from

A

The NPE of the ciliary processes

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10
Q

Volume of aqueous

A

0.2 microliters

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11
Q

How often is aqueous replaced

A

Every 100 minutes

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12
Q

5 main components of the aqueous

A
  1. Bicarbonate
  2. Lactic acid
  3. Ascorbic acid
  4. Chlorides
  5. Glucose

These are also found in blood plasma but in different concentrations

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13
Q

Correlation between aqueous humor comp and attract formation

A

None

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14
Q

The highly transparent and dilute solution of salts, soluble proteins and hyaluronic acid contained within a meshwork of the insoluble protein, collagen

A

Vitreous humor

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15
Q

What is the makeup of vitreous

A

Salts
Soluble proteins
Hyaluronic acid
In collagen

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16
Q

What percentage of vitreous is water

A

98.5% to 99.7%

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17
Q

How is vitreous described

A

As having a CT status and being an extracellular matrix

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18
Q

What are the most important vitreous humor metabolites?

A

Magnesium
Copper
Zinc
Selenium

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19
Q

What is important about magnesium, copper, zinc, and selenium in vitreous humor?

A

They are in the vitamins for AREDS. AREDS 2 is more nutritionally based compared to AREDS 1. Can take theses with vitamin C supplement

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20
Q

___________ has a significant role in the production and secretion of several CT macromolecules of the vitreous body

A

Nonpigmented epithelium of the pars plana

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21
Q

Where is the collagen content the highest in the vitreous humor

A

In the base

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22
Q

Where is the second place that the collagen content is the highest in the vitreous humor

A

Cortex

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23
Q

Where is the collage lowest in the vitreous humor

A

Center

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24
Q

Arrangement of collagen in the vitreous

A

Uniform, 8-16nm in diamter

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25
Q

Viewing the collagen of the vitreous

A

Cannot be seen with a slit lamp, but the pattern of variations in their density and regularity can be seen

26
Q

Density of the Colleen fibril network in the vitreous

A

Differs throughout

27
Q

What are the 3 main types of collagen in the vitreous humor

A

Type II
Type IX
Type XI

28
Q

Which type of collegen is most predominant in vitreous

A

Type 2

29
Q

A fibril forming collagen that accounts for 60-75% of the collagen in vitreous

A

Type 2

30
Q

Has been estimated to represent up to 25% of the collagen in vitreous

A

IX

31
Q

Is a minor (10-25% of total collagen in vitreous) fibril forming collagen that co assembles with the type II collagen to form the core of the heterocyclic fibrils (least role)

A

Type XI

32
Q

Heterotypic

A

In the vitreous, nearly all of the collagen is in thin uniform, and heterotypic fibrils (mixed compositions)

33
Q

What are the non collagen components of vitreous

A
Fibrillin
Opticin
GAGs
Hyaluronic acid 
Hyalocytes 
Fibroblasts
34
Q

Family of glycoproteins that form microfibrils with a characteristic beaded structure.

A

Fibrillin

35
Q

These represent the major structures component of the zonules

A

Fibrillin

36
Q

What is Marfan syndrome caused by

A

Mutations in fibrillin 1

37
Q

Glycoproteins that was initially IDed as the major component in a pool of macromolecules extracted from the surface of vitreous collagen fibrils.

A

Opticin

38
Q

This is a member of the family of extracellular matrix small leucine-rich repeat protein/proteoglycans

A

Opticin

39
Q

What does opticin do

A

Binds growth hormone and GAGs

40
Q

Composed of long chains of repeating units

A

GAGs

41
Q

All GAGs are attached to a protein core except what

A

Hyaluronic acid

42
Q

What is the order of eye structure from most to least GAGs

A

Vitreous
Cornea
Sclera

43
Q

The major vitreal component is a long unbranched molecule coiled into a twisted network

A

Hyaluronic acid

44
Q

This makes things gooey, causes things to be gelatinous. Loss of this liquify things

A

Hyaluronic acid

45
Q

This is a hydrophilic macromolecules located in specific sites within the collagen fibril network and is believed to maintain the wide spacing between fibrils

A

Hyaluronic acid

46
Q

Where is the the concentration of HA the highest?

A

Posteiror cortex

47
Q

Where is there the least HA

A

Center

48
Q

What is the gel structure of HA a result of

A

The interaction of collagen and HA

49
Q

What does HA do

A

Stabilizes the network formed by the collagen strands

50
Q

___ is the predominant GAG in mammalian vitreous

A

HA

51
Q

Composition of HA

A

Linear, polymetric GAG built from networks through entanglement!!

52
Q

How is HA distinguished from other GAGs

A

Not synthesized covalently, linked to a core porting, and it is never sulfated ****

53
Q

These are vitreous cells located in a single, widely spaced layer in the cortex near the vitreal surface and parallel to it

A

Hyalocytes

54
Q

Function of hyalocytes

A

Synthesize HA, synthesize glycoproteins for the collagen fibrils, phagocytized properties

55
Q

Appearance of hyalocytes in different parts of the vitreous

A

Vitreous base are fibroblast like when anterior to the ora serratta. Macrophage like when posteiror to the ora serrata

56
Q

Hyalocytes in the back of the eye

A

Eat more, work less (macrophage)

57
Q

Hyalocytes in the front of the eye

A

Work more, eat less. Fibroblasts like

58
Q

These synthesize the collagen fibrils that run anteroposteriorly and are active in pathologic conditions

A

Fibroblasts

59
Q

Functions of vitreous

A
  • Physical support holding the retina
  • storage for metabolites
  • shock absorber
  • transmits and refracts light, aiding in focusing the rays on the retina
60
Q

How much more vitamin C does vitreous have than plasma

A

40x

61
Q

Vitreous floaters

A

When the surrounding HA and suspending collagen fibrils of the vitreous begin to degenerate, the collagen fibrils will begin to coalesce. When enough of this coalescing occurs, what was once too small to be detected by the retina, becomes evident.

These small condensations of collagen, where the gel of the HA is missing and is replaced with a more liquid substrate, are called vitreous floaters