This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Wound Healing, Tissue Repair and Scar, Subject name: Surgery
In a sutured surgical wound, the process of epithelialization is completed within: 
Select and explain. 
A. 24 hours, B. 48 hours, C. 72 hours, D. 96 hours
B: 48 hours
Answer: B: 48 hours 
Explanation: Healing by first intention Healing of a clean , uninfected surgical incision approximated by surgical sutures Narrow incisional space immediately fills with clotted blood containing fibrin & blood cells ; dehydration of the surface clot forms the well known scab that covers the wound Within 24hrs , Neutrophils appear at the margin of the incision , moving toward fibrin clot. In 24-48 hrs , spurs of the epithelial cells move from the wound edges along the cut margins of the dermis , depositing basement membrane components as they move. By day 3, the neutrophils have been largely replaced by macrophages . Granulation tissue progressively invade the incision space.