Tissue Repair: Regeneration and Fibrosis
Start with the big picture
Regeneration replaces lost cells with native cells, whereas fibrosis replaces damaged tissue with collagenous scar. Repair is shaped by cell type, extracellular matrix integrity, and stem cell niches. Growth factors promote cell proliferation, while TGF-β is a major driver of collagen deposition and fibrosis. Early repair includes granulation tissue, with new capillaries and fibroblasts; matrix composition then changes as the scar remodels. In skin, healing by first intention occurs in clean wounds with closely apposed edges, while second intention follows greater tissue loss and involves more granulation tissue and contraction. Systemic and local factors can delay healing, and abnormal outcomes include wound dehiscence and excessive fibrosis.
What you'll learn
- Distinguish regeneration from fibrosis and identify factors that influence repair.
- Describe how growth factors and TGF-β contribute to tissue repair.
- Outline angiogenesis, granulation tissue formation, and matrix remodeling.
- Compare cutaneous healing by first and second intention.
- Identify systemic and local factors that delay wound healing.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
