1. Tissue Response to Injury
Tissue Healing

2. The Healing Process Inflammatory Response Phase (4 days)
Injury to the cell will change the metabolism (cellular function) and initiate an inflammatory response
Signs of inflammation:
REDNESS (rubor)
SWELLING (tumor)
TENDERNESS AND PAIN (dolor)
INCREASE IN TEMPERATURE (calor)
LOSS OF FUNCTION (function laesa)
Leukocytes and Phagocytes (WBCs) will dispose of injury byproducts via PHAGOCYTOSIS

3. Phagocytosis
Mononuclear Phagocytes/Macrophages will remove debris and begin blood coagulation
Formation of a network of FIBRIN
Epithelial cells migrate along the edges of the wound and FIBROBLASTS enter to regrow capillaries

4. Inflammatory Response

5. Inflammatory response
Immediate Vasoconstriction
First 5-10 minutes
The blood vessels will constrict
Vascular Dilation
24-36 hours
Blood and plasma will flood the area and the tissue will become more PERMIABLE
White blood cells communicate to clean the area of damaged tissues
Clotting will begin

6. Inflammatory response
Chemical Mediators
Histamine – helps with vasodilation and increased cell permeability, sensitizes pain receptors
Leukotaxin - Increase cell permeability, allows for the transfer of WBCs through the cell walls
Necrosin – Phagocytic activity
The amount of swelling that occurs will be in direct relation to the amount of damage to the blood vessels
Leukocytes will release
Bradykinin – increases cell permeability, increases pain response
Prostoglandins – increase permeability of blood vessels and surrounding tissues
This increases the amount of space that WBCs have to move

8. Clot formation Platelets adhere to form a sticky matrix
Thrombin creates fibrin clots that shot off blood supply to the area

9. The healing process Fibroblastic Repair Phase (day 4- week 6)
Scar formation and repair of injured tissues begins immediately after an injury

10. Fibroblastic repair Revascularization Wound Contraction
Growth of new capillaries is stimulated by a lack of O2
Fibroblasts begin laying collagen
This forms a seal over the injured area
Wound Contraction
Fibroblasts begin towards the edges of the wound and move towards the center
There is continuous replacement of tissue as the wound heals

12. The healing process Maturation/ Remodeling (Week 6 – 2-3 years)
Realignment or remodeling of the collagen fibers that make up scar tissue
Parallel to the lines of tension
After approximately 3 weeks a NONVASCULAR scar will exist
Wolff’s Law
Bone and soft tissue will respond the physical demands that are placed on them
This leads to remodeling and realignment along the lines of TENSILE FORCE

13. Factors that impede healing
The extent of the injury
Edema
Hemorrhage
Poor vascular supply
Separation of tissue
Muscle spasm
Corticosteroids
Keloids
Infection
Humidity/climate
Health, age, nutrition

14. Pain Acute Pain last less than 6 months Chronic Pain will last longer
Referred Pain occurs away from the actual site of irritation
Myofascial Pain
Trigger points
Sclerotomic Pain
Deep aching pain that is localized and supplied by a single nerve root
Dermatomic Pain
An area of skin supplied by a single nerve root, sharp and localized

15. Quick write
Why is it necessary to understand the different stages of healing?
Write a paragraph on your thoughts and we will discuss this as a class