Tissue+Healing+2023-1.ppsx

Tissue Healing and Repair Chapter 5 Objectives Outline the body’s response to tissue injuries Identify the body’s first response to tissue injury Define inflammation Describe the steps of wound repair Describe regeneration Describe how tissue healing is classified Learn proper terminology Tissu...

Tissue Healing and Repair Chapter 5 Objectives Outline the body’s response to tissue injuries Identify the body’s first response to tissue injury Define inflammation Describe the steps of wound repair Describe regeneration Describe how tissue healing is classified Learn proper terminology Tissue Injuries HBC Falls Bites / Scratches Wounds Broken bones Surgical incisions Body’s Response To Injury First response = Inflammation It is the body’s attempt to:  Limit the damage caused by the injury  Isolate the injury  Prevent more damage from occurring Area becomes red, warm, tender and swollen (Rubor, Calor, Dolor and Tumor) Possible decreased function of the injured part Inflammation Nonspecific reaction to injury or disease Occurs whether there is tramatic injury or an infectious process Extent is dependent on the type of tissue involved and the severity of the injury or illness Steps in the Process of Inflammation 5-10 minute vasoconstriction  Aids in the control of hemorrhage Sustained period of vasodilation & increased vascular permeability (due to histamine & heparin)   Results in increased blood flow that, w/ inc permeability, causes the clinical signs of heat and redness Increases the supply of oxygen and nutrients to the active cells of the damaged tissue Fluid from plasma flow into the affected area causing swelling of soft tissue Swelling puts pressure on and irritates the Inflammation Clot formation begins  Slows bleeding  Helps isolate any bacteria or pathogens Clot forms when platelets become sticky and clumped Fibrinogen which is found in large amounts in swollen tissue is converted to fibrin  forms an insoluble netlike structure that weaves around the platelets and supports and stabilizes the newly formed clot  forms framework supporting the movement of cells throughout the inflamed site  Clots formed on external surfaces dry out and form a Inflammation Phagocytic cells (neutrophils & macrophages) move into the site  These cells aid in removal of debris and bacteria  When degenerating & dead these cells may accumulate as purulent material (pus) The increased blood flow causes dispersion & a decrease in levels of histamine & heparin in the affected area -> return of normal capillary size & permeability w/ cessation of blood flow & fluid  Swelling, heat and redness begin to subside Wound Repair Begins soon after injury occurs Organization = Formation of granulation tissue Granulation tissue forms beneath the clot or scab  Bright pink, glistening  Composed of a layer of collagen infiltrated by numerous small permeable capillaries  Supplies oxygen and nutrients Granulation tissue produces substances that inhibit bacteria making it resistant to infection Exuberant Granulation Tissue = Proud flesh = Granulation tissue that has become too thick and extends above the epithelial layer Regeneration Occurs at same time as organization Epithelial cells around the wound edges actively divide to lay down a new layer of tissue over the granulation bed = Epithelialization The scab falls off Granulation tissue is slowly replaced by fibrous scar tissue (fibrosis) which contracts & pulls wound closed When epithelialization is complete, it may cover the scar or not depending on severity of the injury & size of scar formed Scar tissue is strong but is less flexible than normal tissue Function of the damaged tissue may remain impaired even after scar shrinks (See text pg Classification of Wound Repair Based on mechanism of healing & the proximity of the wound edges First intention – wound edges held in close apposition as when sutured; no granulation tissue or scar formed Second intention – wound edges separated due to tissue loss and/or defect is filled with exudate and debris +/- infection; tissue allowed to heal via granulation tissue & scar formation occurs Review Outline the body’s response to tissue injuries What is the body’s first response to tissue injury? Define inflammation Describe the steps of wound repair (in outline form) Describe regeneration Understand the classification of tissue healing Know the proper terminology