Collagen And The Eye

Question 1

4 types of embryonic CT

Answer 1

Mesenchymal

Mucous

Supporting

Hematopoietic Tissue (blood and bone marrow)

Question 2

What is a fixed cell? Ex?

Answer 2

Cells that are made and reside in the same tissue.

Fibroblasts, they’re made and reside in the CT

Question 3

What is a wandering cell? Ex?

Answer 3

Cells that are not fixed to their tissue and they travel.

Eosinophils, mast cells, and plasma cells (derived from B-lymphocytes)

Question 4

What do fibroblasts produce?

Answer 4

Procollagen

Question 5

Found in connective tissue and are flexible/have a high tensile strength

Answer 5

Collagen fibers

Question 6

Collagen structure

Answer 6

Procollagen single strands combine to make a triple helix (collagen fibril), then collagen fibrils combine to make a collagen fiber

Its tensile strength is greater than steel!

Question 7

How many types of collagen are recognized in humans?

Answer 7

16

Question 8

Which type of collagen makes up 90% of collagen in the body?

Answer 8

Type 1

Question 9

3 catergoes of collagen

Answer 9

Fibrous

Non-fibrous

Filamentous

Question 10

Collagen that is seen in an electron microscope as thick fibers

Ranges from 200 nm in skin/tendon to 25 nm in cornea

Answer 10

Fibrous collagen

Question 11

Range of fiber size in the cornea

Answer 11

25-30 nm

Uniform

Question 12

Variable fiber size in the skin

Answer 12

20 to 200 nm

Question 13

Groups of collagen in the skin/cornea

Answer 13

Genetic types I, II, III collagens

Question 14

Collagen that forms the thin basement membranes separating the fibrous stromatolites tissue from the cells

Answer 14

Non-fibrous collagen

Question 15

Size and location of non-fibrous collagen

Answer 15

25 nm in capillaries and golmeruli

200 nm in the lens

Question 16

What is the only catergory of collagen to be found in non-fibrous collagen?

Answer 16

Type IV collagen

IN ALL BASEMENT MEMBRANES

Question 17

Collagens that form loosely aggregates fibers with little of no periodicity

Answer 17

Filamentous collagen

Question 18

Filamentous collagen can be subdivided into what? And what types are included?

Answer 18

Pericellular and matrix collagen

Types VI, VII, IX, and X

Question 19

Collagens of the Cornea

Answer 19

Transparent tissue containing fine collagen fibers of UNIFORM diameter with a high degree of spatial organization

Question 20

Collagens of the Sclera

Answer 20

Opaque tissue containing thick interwoven collagen fibers

Structural, strength and resilience due to interlacing collagen fibers

30 nm - 300 nm

Mainly type 1 and some type III

Question 21

Collagen of the Vitreous body

Answer 21

Polysaccharide gel containing small amounts of fine collagen fibers

7-13 nm

Embedded in a hyaluronate gel

Function to stabilize shape of gel and reduce compressibility

Mainly type II collagen

Question 22

Collagen of the retina

Answer 22

Typical thin basement membrane

Non-fibrous

Bruch’s membrane

Type IV

Question 23

Collagen of the choroid

Answer 23

Highly vascularized tissue of the iris…?

Question 24

The human cornea contains __% collagen

Answer 24

90

Question 25

Vitreous body contains both:

Answer 25

Collagen fibers and elastic fibers For maintenance of a) intraocular pressure and b) acting as a shock absorber

Question 26

What type of collagen is in the lens capsule?

Answer 26

Type IV non-fibrous

Question 27

Membrane located under the corneal stroma, that separated the corneal stroma from the corneal epithelium Consists of what 2 types?

Answer 27

Descemet's membrane 90% type IV and 10% type V

Question 28

Type VI collagen is found where

Answer 28

Extra cellular matrix of the cornea Throughout the corneal stroma

Question 29

Where is type VIII found?

Answer 29

Descemet's membrane Synthesized by the corneal endothelial cells

Question 30

The vitreous body contains a lot of what type?

Answer 30

Type IX Filamentous, but has same cross-linking as fibrous

Question 31

When the cornea bulges, due to problems with the collagen

Answer 31

Keratoconus

Question 32

Collagen is important in the cornea because..

Answer 32

It plays an important role in the transparency

Question 33

The corneal strength relies on:

Answer 33

The head-to-tail orientation Cross linking More linking, stronger the tissue

Question 34

When the need to strengthen the cornea arises, what procedure is done?

Answer 34

Corneal Cross Linking