1- Principles of wound healing

Question 1

Name the 3 phases of wound healing

Answer 1

Inflammatory (& haemostasis), proliferative, maturation

Question 2

What activates the clotting cascade in a wound?

Answer 2

Damage to the endothelium

Question 3

List the key steps of haemostasis when an injury is made to the skin

Answer 3

Tissue damage
blood leakage from vessels
activation of clotting cascade - intrinsic and extrinsic
Platelet aggregation and release of cytokines
Stabilisation of platelet plug by fibrin formation

Question 4

When does the inflammatory phase begin?

Answer 4

Occurs in the first 72hours after injury- overlaps with haemostasis

Question 5

What occurs in the inflammatory phase?

Answer 5

Vasodilation - allows blood flow to allow substances to migrate
Cytokines in fibrin clots attract WBC - neutrophils & macrophages
Destruction of cells by phagocytosis (Clean up bacteria & devitalised tissue)

Question 6

What is formed in the proliferation phase & how is it identified?

Answer 6

Granulation tissue - bright red & shiny tissue

Question 7

What cells produce collagen, extracellular matrix & elastin?

Answer 7

Fibroblasts

Question 8

What is the pale pink tissue that forms on top of the granulation tissue?

Answer 8

Epithelial tissue

Question 9

What occurs in the maturation phase?

Answer 9

Remodelling
Type III collagen is replaced by Type 1 (mature)
Cross-linking of collagen
Increase in tensile strength

Question 10

Name 3 factors that affect wound healing?

Answer 10

Patient age, co-morbidities, Nutrition status
Wound factors = infection, location
Concurrent treatments = Corticosteroids, radiation