Wound Healing & Tissue Repair

Question 1

How does first and second intention wound healing differ?

Answer 1

First intention occurs in wounds with opposed edges. Second intention occurs in wounds with separate edges and involves a more prominent inflammatory reaction and scar formation

Question 2

TGF-B & PDGF have similar functions. What is the primary difference between these proteins, with respect to function?

Answer 2

TGF-B inhibits collagenase, while PDGF secretes collagenase to eliminate immature collagen

Question 3

What proteins stabilize and promote neovascularization during tissue repair?

Answer 3

APO 1 - recruits pericytes
PDGF - recruits smooth muscle
TGF-B - stabilizes vessels

Question 4

What types of cells have a high replacement capacity?

Answer 4

Labile cells

Question 5

What process follows tissue damage when the original tissue architecture is intact, with little destruction?

Answer 5

Resolution

Question 6

What protein is especially important for angiogenesis as part of wound repair?

Answer 6

FGF - also has all the functions of TGF-B

Question 7

What proteins function in monocyte chemotaxis, fibroblast migration, and collagen synthesis?

Answer 7

TGF-B & PDGF

Question 8

What immune cell is first present following a tissue injury?

Answer 8

Neutrophils - they are replaced by macrophages after ~24 hours

Question 9

What proteins act as fibrogenic cytokines?

Answer 9

TNFa & IL-1

Question 10

Hematopoietic stem cells are capable of producing what other types of cells?

Answer 10

Blood cells, bone marrow, hepatocytes, neurons

Question 11

A patient is 1 month post-surgery and wants to begin vigorous activity. The surgeon advises against this. Why is this?

Answer 11

1-month post-op, the tissue has regained only approx. 20% of its original strength. Wounds can take 6-12 months to regain full strength

Question 12

What is it called when scar tissue grows beyond the bounds of the wound and will not regress?

Answer 12

Keloid

Question 13

True/False. Any level of inflammation will initiate repair processes.

Answer 13

True

Question 14

True/False. Tissue remodeling is a balancing act. Collagen and EGM is constantly degraded and maintained.

Answer 14

True. MMPs degrade collagen and ECM, while TIMPS inhibit MMPs

Question 15

An ulcer forms over a wound. What is the primary reason why this may occur?

Answer 15

Inadequate vascularization

Question 16

What are the functions of VEGF?

Answer 16

Promotes angiogenesis, endothelial migration & proliferation, increases vascular permeability

Question 17

What zinc-dependent protein degrades collagen and ECM during tissue remodeling?

Answer 17

Matrix mettaloproteinases

Question 18

What factors may influence wound healing?

Answer 18

Age, nutritional deficiencies, metabolic diseases, catabolic state, systemic drugs

Question 19

What type of collagen forms the primary scar?

Answer 19

Collagen I

Question 20

What is contracture?

Answer 20

Contracture is the pulling of the tissue together during wound repair. Exaggeration of this process can cause deformities in the tissue

Question 21

What protein is most important in fibroblast proliferation and is present in chronic fibrotic diseases?

Answer 21

TGF-B

Question 22

What is it called when a wound ruptures due to increased abdominal pressure?

Answer 22

Wound Dehiscence

Question 23

What tissue repair proteins have intrinsic tyrosine kinase activity?

Answer 23

EGF & FGF