Which cells are active after an injury to begin building collagen?

Which cells are active after an injury to begin building collagen?

• A. Fibroblasts
• B. Macrophages
• C. Chondrocytes
• D. Mast cells

Answer: (A)

Fibroblasts are the cells that drive the collagen-building phase of wound repair. After injury, they migrate into the wound bed and, in response to signals like TGF-β and PDGF, start synthesizing and secreting extracellular matrix proteins, especially collagen. This collagen deposition lays down the scaffold for granulation tissue and, over time, scar formation. Fibroblasts also differentiate into myofibroblasts to contract the wound as healing progresses. Macrophages play a crucial role by cleaning up debris and releasing cytokines that recruit and activate fibroblasts, but they aren’t the primary collagen producers. Chondrocytes are cartilage cells and aren’t involved in typical skin wound healing. Mast cells contribute to inflammation and vascular changes, not collagen synthesis.

Fibroblasts are the cells that drive the collagen-building phase of wound repair. After injury, they migrate into the wound bed and, in response to signals like TGF-β and PDGF, start synthesizing and secreting extracellular matrix proteins, especially collagen. This collagen deposition lays down the scaffold for granulation tissue and, over time, scar formation. Fibroblasts also differentiate into myofibroblasts to contract the wound as healing progresses.

Macrophages play a crucial role by cleaning up debris and releasing cytokines that recruit and activate fibroblasts, but they aren’t the primary collagen producers. Chondrocytes are cartilage cells and aren’t involved in typical skin wound healing. Mast cells contribute to inflammation and vascular changes, not collagen synthesis.