Wound healing

Question 1

Describe the sequence of events involved in healing by first intention - at time: 0 hours

Answer 1

Wound fills with blood clot

Question 2

Describe the sequence of events involved in healing by first intention - at time: 3-24 hours

Answer 2

Inflammation, recruitment of neutrophils.

Question 3

Describe the sequence of events involved in healing by first intention - at time: 24-48 hours

Answer 3

Fibroblasts migrate to wound and proliferate
Granulation tissue forms.
(Granulation tissue is composed of loose connective tissue, with thin vessels formed by angiogenesis, which are prone to leaking and causing oedema)

Question 4

Describe the sequence of events involved in healing by first intention - at time: Day 3-5

Answer 4

Macrophages replace neutrophils
Collagen deposition
TGF-beta from macrophages drives further fibroblast activity
Granulation tissue formation and neovascularization reaches a peak at Day 5

Question 5

Describe the sequence of events involved in healing by first intention - at time: Week 2

Answer 5

Scar tissue accumulates
Inflammation subsides
Reduction in vascularisation
Wound contraction

Question 6

When does a scar reach 10% of its pre-morbid strength? When does a scar reach 80% of its pre-morbid strength?

Answer 6

10% at 7 days

80% at 3 months

Question 7

Describe some differences in wound healing by secondary intention and by primary intention.

Answer 7

In healing by secondary intention, the following features are more intense than they are in primary intention:

• Inflammatory reaction
• Granulation tissue
• Wound contraction (with myofibroblasts)