Tissue Repair

Question 1

What are the 4 phases of tissue healing?

Answer 1

1. Hemostatsis - bleeding
2. Inflamnation
3. Proliferation
4. Remodeling

Question 2

What is the hemostatsis phase?

Answer 2

1. Bleeding phase.
2. Platelets into contact with collagen resulting in activation/aggregation.
3. Prothrombin is converted to thrombin and fibrogen is converted to fibrin. These form fibrin cross-linking to strengthen the platelet clumps into a stable clot. Coagulation 4-6 hrs.

Question 3

What is the inflammation phase?

Answer 3

1. Focuses on destroying bacteria/removing debris
2. White blood cells (neutrophils) ented the wound and destroy/remove bacteria
3. Inflammatory response releases inflammatory cytokines e.g serotonin, Bradykinin, histamine.
4. Neutrophils leave macrophages enter clear debris.
5. Secretion of growth factors/proteins to repair. Often associated with the 5 cardinal signs of inflammation-rubor (redness), calor (heat), dolor (pain), tumor (swelling), functio laesa (function loss).

Question 4

What are the five cardinal signs of inflammation?

Answer 4

1. Rubor (redness)
2. Calor (heat)
3. Dolor (pain)
4. Tumor (swelling)
5. Functio laesa (function loss).

Question 5

What is the proliferation phase?

Answer 5

Distinct stages within the phase.

1. Filling the wound- shiny, deep, red granulation tissue fills the wound ved with connective tissue and new blood vessels are formed.
2. Contraction of wound margins- wound margins pulls towards the centre of the wound.
3. Covering the wound (epithelialisation)-epithelial cells arise from the wound bed of margins and migrate across the wound (leap frog fashion) until completely covered..4-24 days.

Question 6

What is the remodeling phase?

Answer 6

1. New tissue slowly gain strength/flexibility.
2. Collagen fibres reorganise the tissues remodel/matures.
3. Increase in tensile strength (max strength limited to 80% of preinjured strength) 21days to 2 years