Tissue Repair Regeneration Replacement of destroyed tissue by

Tissue Repair · Regeneration · Replacement of destroyed tissue by the same kind of cells · Fibrosis · Repair by dense fibrous connective tissue (scar tissue) · Determination of method · Type of tissue damaged · Severity of the injury Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 69

Process • Wound occurs. Within minutes hemostasis begins. Vessels constrict, limit blood flow. (hemostasis – literally means “blood / standing still”) •

Events in Tissue Repair · Tissue injury causes series of events · Release of inflammatory chemicals. . (ex. Histamine) causes Capillaries to dilate & become very permeable · Allows white blood cells, antibodies, clotting proteins to leak into the tissue. · Clot forms & Walls off injured area Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 70

Inflammation • Area feels warm, is red, puffy, swollen, and feel pain. macrophage cells clean up the mess – Eat up dead stuff and bacteria.

Granulation! • Formation of granulation tissue – a “scab” and what is going on under it. • Granulation – pink looking tissue made of newly forming capillaries, macrophages, and fibroblasts that make new collagen fibers

Regeneration of tissue • Surface epithelium begins to regenerate covering granulation tissue of scab. • New Epithelial tissue w/underlaying layer of scar tissue…. SCAR may/may not be visible.

What slows down wound healing? • Smoking • Diabetes • Clotting disorders To name a few….

Regeneration of Tissues · Tissues that regenerate easily · Epithelial tissue · Fibrous connective tissue and bone · Tissues that regenerate poorly · Skeletal muscle · Tissues that are replaced largely with scar tissue · Cardiac muscle · Nervous tissue within the brain and spinal cord Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 71