Britannica Sources used in this answer

How does tissue regeneration differ from scar formation during healing?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Tuberculosis — disease A doctor examining chest X-rays of patients infected with tuberculosis, which remains one of the world's deadliest diseases.

Tissue regeneration and scar formation are two distinct biological responses to injury, differing primarily in their ability to restore original tissue structure and function.

Tissue Regeneration

Regeneration occurs when damaged cells are capable of proliferation, allowing the body to replace lost tissue with new cells of the same type. This process is most successful in tissues with simple architectures, such as the skin's surface or epithelial layers. When regeneration is effective, the original framework and function of the tissue are restored.1

Scar Formation (Repair)

Repair, or scar formation, occurs when tissue damage is substantial or the original architecture is too complex to be reconstructed. This process involves:1
* Granulation Tissue: The formation of a delicate, vascularized framework of connective tissue created by fibroblasts and new blood vessels.1
* Collagen Deposition: Fibroblasts produce collagen to provide mechanical strength to the area.1
* Scarring: The final result is a scar composed of densely packed collagen.1

Unlike regenerated tissue, scar tissue is often less voluminous than the original, which can lead to organ contraction, distortion, or loss of specialized functions, such as the inability of skin scars to tan or produce hair.12