Surgery: Wound Care

Question 1

with a tissue injury, what are the 4 possible outcomes?

Answer 1

1. normal repair
2. regeneration
3. deficient healing
4. excessive healing

Question 2

4 phases of wound healing

Answer 2

Hemostasis
Inflammation
Proliferation
Remodeling

Question 3

what happens in hemostasis? (6)

Answer 3

1. Blood clotting
   - Protease activation ( exposed ECM)
   - Thrombin activates Fibrinogen to Fibrin
2. Fibrin molecule proliferate
   - -> Fibrin plug traps RBCs and platelets
3. Capillary endothelial cells and vascular smooth muscle cell contract
4. plt degranulation
5. fibroblasts attracted to site
6. angiogenesis

Question 4

what cells are involved in the inflammatory process

Answer 4

inflammatory cells: Mast cells, Neutrophils, Macrophages, T and B cells
Regulatory molecules: Chemokines + Cytokines

Question 5

what do neutrophils do?

Answer 5

First cells to respond to soluble mediators

• Interactions with adhesion molecules and integrins –>activate the leukocytes
• ->Release elastase and collagenase

Question 6

what do macrophages do? (2)

Answer 6

Essential to normal wound healing

• Phagocytosis and removing devitalized matrix
• Mediate transition to the proliferative phase

Question 7

Matrix metalloproteases (MMPs) do what?

Answer 7

in inflammation: remove damaged componenents of the ECM

in proliferation: essential for fibroblast migration

Question 8

what occurs in proliferation?

Answer 8

fibroblast migration
synthesis of scar matrix
angiogenesis
epitheliaziation (Keratinocyte proliferation and migration)

Question 9

what occurs in Remodeling?

Answer 9

Granulation tissue matures
Tissue tensile strength increases
Changes in type and amount of collagen
Collagen reorients (no net collagen production)

Question 10

what cells are the main players in each phase of healing?

Answer 10

Hemostasis: Platelets, Fibrin matrix, cytokines, GFs
Inflammation: Neutrophils, macrophages, Cytokines, GFs, proteases
Proliferation: Fibroblasts-collagen
Remodeling: MMPs, TIMPs