Tissue Repair Pages 100-101

Methods of Tissue Repair Two methods: Regeneration (Replacement) destroyed tissue is replaced by the same kind of cells; Mitosis: cells divide to make new ones Fibrosis (Repair) dense (fibrous) connective tissue (scar tissue) replaces the original tissue Method is determined by: Type of tissue damaged Severity of the injury © 2015 Pearson Education, Inc.

Events in Tissue Repair Inflammation Capillaries become very permeable Clotting proteins migrate into the area A clot (visible fibers from blood) walls off the injured area Granulation tissue forms Growth of new capillaries Rebuild of collagen fibers to form a bridge Surface epithelium grows underneath © 2015 Pearson Education, Inc.

Tissue Repair = SCAR TISSUE The severity of the wound determines the extent of scarring Scar tissue: Many collagen fibers Lacking blood supply Very strong No flexibility or elasticity Loss of normal function of original tissue © 2015 Pearson Education, Inc.

Tissues that: regenerate easily/well regenerate poorly Epithelial tissue (skin and mucous membranes) Fibrous connective tissues and bone regenerate poorly Skeletal muscle Dense connective tissues: tendons, ligaments Are replaced largely with scar tissue Cardiac muscle Nervous tissue within the brain and spinal cord © 2015 Pearson Education, Inc.