What type of collagen is formed first in the proliferation stage?

• A. Type 1
• B. Type 3
• C. Type 2
• D. Type 4

Answer: (B)

In the proliferation stage of wound healing, fibroblasts rapidly lay down a flexible collagen scaffold to fill the wound and support new tissue growth. The first collagen produced is type III, which is quick to form and helps create granulation tissue and vascular ingrowth. This early scaffold is relatively soft, allowing the tissue to expand and remodel. As healing continues into remodeling, type III is gradually replaced by type I collagen, which provides greater tensile strength to the repaired tissue. Types II and IV serve different roles—type II in cartilage and type IV in basement membranes—and are not the initial collagen laid down in wound healing. So, type III is the best answer because it is the initial collagen deposited during the proliferation phase.