Pathoma - Wound healing

Question 1

Examples of labile tissues

Answer 1

Stem cells that continuously recycle

e.g. small and large bowel, skin, bone marrow

Question 2

Examples of stable tissues

Answer 2

Cells that are quiescent but can regenerate when necessary

e.g. hepatocytes

Question 3

Examples of permanent tissues

Answer 3

Lack regeneration potential:

(1) Myocardium
(2) Skeletal musle
(3) Neurons

These cells must heal via repair (cannot heal via regeneration)

Question 4

What are the 3 components of granulation tissue?

Answer 4

(1) Fibroblasts
(2) Capillaries
(3) Myofibroblasts

Question 5

What is the function of fibroblasts

Answer 5

Deposition of Type III collagen

Question 6

What is the collagen transition involved in scar formation

Answer 6

Type III collagen replaced with Type I collagen

Question 7

What enzyme is required to remove type III collagen

Answer 7

Collagenase

Question 8

What is the cofactor for Collagenase

Answer 8

zinc

Question 9

What role does TGF-a play in tissue repair

Answer 9

TGF-a is an epithelial and fibroblast growth factor

Question 10

What role does TGF-B play in tissue repair

Answer 10

TGF-b is an important fibroblast growth factor + anti-inflammation

Question 11

What role does Platelet-derived growth factor (PDGF) play in tissue repair

Answer 11

growth factor for endothelium, smooth muscle, and fibroblasts

Question 12

What role does fibroblast growth factor (FGF) play in tissue repair

Answer 12

important for angiogenesis, also mediates skeletal development

Question 13

What role does vascular endothelial growth factor (VEGF) play in tissue repair

Answer 13

important for angiogenesis

Question 14

What is the function of myofibroblasts

Answer 14

Contraction of the wound after it has been filled with granulation tissue

Question 15

What contains Type I collagen

Answer 15

Bone, skin, tendon, fascia, cornea, late wound repair

Question 16

What disease has decreased collagen type I production

Answer 16

Osteogenesis imperfecta

Question 17

What contains Type II collagen

Answer 17

Cartilage, vitreous body

Remember: 
1 - strong
2 - slippery
3 - bloody
4  - BMs

Question 18

What contains Type III collagen

Answer 18

skin, blood vessels, uterus, granulation tissue

Question 19

What disease has deficient type III collagen

Answer 19

Vascular Ehlers-Danlos

Question 20

What contains Type IV collagen

Answer 20

Basement membrane

Question 21

What disease has deficient type IV collagen

Answer 21

Alport syndrome

Question 22

What is the collagen deficiency in Ehlers-Danlos

Answer 22

Type V

Question 23

What is the role of vitamin C in wound repair

Answer 23

hydroxylation of proline and lysine pro-collagen residues

Question 24

What is the role of copper in wound repair

Answer 24

Copper is a cofactor for lysyl oxidase, which cross-links lysine and hydroxylysine to form stable collagen

Question 25

What is the role of zinc in wound repair

Answer 25

Cofactor for collagenase, which is needed to replace Type III collagen with Type I

Question 26

What collagen is in excess in keloids

Answer 26

Type III