A

David

Darling

wound healing

wound healing
wound healing, key to diagram

A wound is first sealed by a blood clot (see diagram A in the illustration above). As healing progresses macrophages move in (B) to remove wound debris such as dried blood, bacteria, and damaged cells. When the fresh layer of skin grows across the site (C) the remains of the blood clot are sloughed off in the form of a scab.