Essentials of Anatomy & Physiology Fifth edition Seeley • Stephens • Tate Chapter 4 Tissue Repair Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig. 4.5h

Fig. 4.6c

Fig. 4.7

Inflammation The function of the inflammatory response is to isolate and destroy harmful agents. The inflammatory response produces five symptoms: Redness Heat Swelling Pain (ouch!!) Disturbance of Function

Mediators of Inflammation Chemical substances that are released or activated in the injured tissues. Histamine (released by mast cells) Kinins Prostaglandins Leukotrienes Functions: Dilation of blood vessels, Edema, “Walling of the injury w/fibrin”, Neutrophils move in to eat bacteria: fights infection Macrophages eat dead tissue debris Neutrophils + dead stuff = Pus

Tissue Repair Substitution of viable cells for dead cells Regeneration = new cells are same type & normal function is usually restored Replacement = new type of tissue develops = scar & some loss of function. 1) Fresh wound cuts through the epithelium & underlying connective tissue 2) After about 1 week, a scab is present and new E.T. is growing into the wound. 3) After about 2 weeks, the E.T. has completely grown into the wound & fibroblasts have formed granulation tissue 4) After about 1 month, the wound is completely closed & the granulation tissue is replaced w/new C.T.P.