Wound healing

Steps in wound healing ::

1. Activation of coagulation cascade - formation of a clot.
2. Within 24 hrs - neutrophil come towards the clot.
3. Day 3 - macrophages come and granulation tissue forms. Collagen fibres come at incision margins.
4. Day 5 - neovascularization reaches its peak as granulation tissue fills the space.
5. 2nd week - continous collagen accumulation and fibroblast proliferation. Blanching begins.
6. End of 1st month - scar formed.

Wound strength - at 1 week is 10% of unwounded skin.
Wound strength reaches approx. 70- 80% of normal by 3 months but doesn't improve beyond that.

In healing by second intention or reunion, wound contraction mediated by myofibroblasts is seen which is not seen in primary intention.