Tissue Healing & Repair

Question 1

_{<strong>TISSUE INJURIES</strong>}

Answer 1

• HBC (hit by car)
• Falls
• Bites / Scratches
• Wounds
• Broken bones
• Surgical incisions

Question 2

^{BODY’S RESPONSE TO INJURY}

_{First response<strong> = INFLAMMATION</strong>}

Answer 2

_{It is the body’s attempt to:}

• ^{Limit the damage caused by the injury}
• ^{Isolate the injury}
• ^{Prevent more damage from occuring}
• _{Are becomes red, swollen, hot and tender}
• _{Possible decreased function of the injured part}
• _{Nonspecific reaction to injury or disease}
• _{Occurs whether there is traumatic injury or an infectious process}
• _{Extent is dependant on the type of tissure involved & the severity of the injury or illness}

Question 3

_{<strong>STEPS in the PROCESS of INFLAMMATION</strong>}

Answer 3

1. 5-10 minute vasoconstriction
   * aids in the control of hemorrhage

• Sustained period of vasodilation
• Causes the clinical signs of heat & redness (due to the increased blood flow/inc permeability)
• Increases the supply of oxygen & nutrients to the active cells of the damaged tissue

2. Fluid from plasma flow into the affected area causing swelling of soft tissue
   * This causes irritates the nerve endings causing pain
3. Clot formation begins

• slows bleeding
• helps isolate any bacteria or pathogens

Fibrinogen** which is found in large quantities of swollen tissue is converted to **fibrin

• forms an insoluble netlike structure that weaves around the platelets & supports & stabilizes the newly formed clot
• forms framework supporting the movement of cells throughout the inflamed site
• dries out & forms a scab

4. Phagocytic cells (neutrophils & macrophages) move into the site

• These cells aid in removal of debris & bacteria
• when degenerating & dead these cells may accumulate as purulent material (pus)

5. The increased blood flow causes dispersion & a decrease in levels of histamine & heparin in the affected area -> return to normal capillary size & permeability w/ cessation of blood flow & fluid
   * Swelling, heat & redness begin to subside

Question 4

_{WOUND REPAIR}

^{Begins soon after injury occurs}

ORGANIZATION

Answer 4

Organization

^{= Formation of Granulation Tissue}

• ^{Granulation tissue forms beneath the clot or scab}
  
  • ^{Bright pink, glistening}
  • ^{Composed of a layer of collagen filtrated by numerous small permeable capillaries}
    
    • ^{Supplies oxygen & nutrients}
• ^{Granulation tissue produces substance that inhibit bacteria making it resistant to infection}

Question 5

^{WOUND REPAIR}

EXUBERANT GRANULATION TISSUE

Answer 5

= Pround flesh

^{= Granulation tissue that has become too thick & extends above epithelial layer}

Question 6

^{WOUND REPAIR}

^{<strong><span>_REGENERATION</span></strong>}

Answer 6

Regeneration

• occurs 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 contract & pulls wound closed
• When epithelization 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

Question 7

CLASSIFICATION OF WOUND REPAIR

Answer 7

Based on mechanism of healing & proximity of the wound edges

First intention - wound edges held in close oppositionas when sutured; no granulation tissue or scar formed

Second intention - wound edges are separated due to tissue lost & the defect is filled with exudate & debris +/- infection; tissue allowed to heal via granulation tissue & scar formation