Slide 1 Figure 4 12 Tissue repair of

Slide 1 Figure 4. 12 Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Scab Blood clot in incised wound Regenerating epithelium Regenerated epithelium Epidermis Area of granulation tissue ingrowth Vein Fibroblast Macrophage Migrating white blood cell Artery Inflammatory chemicals 1 Inflammation sets the stage: • Severed blood vessels bleed and inflammatory chemicals are released. • Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins and other plasma proteins to seep into the injured area. • Clotting occurs; surface dries and forms a scab. Copyright © 2010 Pearson Education, Inc. 2 Organization restores the blood 3 supply: • The clot is replaced by granulation tissue, which restores the vascular supply. • Fibroblasts produce collagen fibers that bridge the gap. • Macrophages phagocytize cell debris. • Surface epithelial cells multiply and migrate over the granulation tissue. Fibrosed area Regeneration and fibrosis effect permanent repair: • The fibrosed area matures and contracts; the epithelium thickens. • A fully regenerated epithelium with an underlying area of scar tissue results.

Slide 2 Figure 4. 12 Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Scab Epidermis Blood clot in incised wound Inflammatory chemicals Vein Migrating white blood cell Artery 1 Inflammation sets the stage: • Severed blood vessels bleed and inflammatory chemicals are released. • Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins and other plasma proteins to seep into the injured area. • Clotting occurs; surface dries and forms a scab. Copyright © 2010 Pearson Education, Inc.

Figure 4. 12 Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Regenerating epithelium Area of granulation tissue ingrowth Fibroblast Macrophage 2 Organization restores the blood supply: • The clot is replaced by granulation tissue, which restores the vascular supply. • Fibroblasts produce collagen fibers that bridge the gap. • Macrophages phagocytize cell debris. • Surface epithelial cells multiply and migrate over the granulation tissue. Copyright © 2010 Pearson Education, Inc. Slide 3

Figure 4. 12 Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Slide 4 Regenerated epithelium Fibrosed area 3 Regeneration and fibrosis effect permanent repair: • The fibrosed area matures and contracts; the epithelium thickens. • A fully regenerated epithelium with an underlying area of scar tissue results. Copyright © 2010 Pearson Education, Inc.

Slide 5 Figure 4. 12 Tissue repair of a nonextensive skin wound: regeneration and fibrosis. Scab Blood clot in incised wound Regenerating epithelium Regenerated epithelium Epidermis Area of granulation tissue ingrowth Vein Fibroblast Macrophage Migrating white blood cell Artery Inflammatory chemicals 1 Inflammation sets the stage: • Severed blood vessels bleed and inflammatory chemicals are released. • Local blood vessels become more permeable, allowing white blood cells, fluid, clotting proteins and other plasma proteins to seep into the injured area. • Clotting occurs; surface dries and forms a scab. Copyright © 2010 Pearson Education, Inc. 2 Organization restores the blood 3 supply: • The clot is replaced by granulation tissue, which restores the vascular supply. • Fibroblasts produce collagen fibers that bridge the gap. • Macrophages phagocytize cell debris. • Surface epithelial cells multiply and migrate over the granulation tissue. Fibrosed area Regeneration and fibrosis effect permanent repair: • The fibrosed area matures and contracts; the epithelium thickens. • A fully regenerated epithelium with an underlying area of scar tissue results.