Healing

Question 1

Three phases of healing

Answer 1

Inflammatory, Proliferation, Maturation

Question 2

Inflammatory Phase

Answer 2

1. Fibrin Clot formation
   2.Polymorphonuclear Neutrophil organization—24-48 hrs after injury
2. Pavementing (PMNs attach to vessel walls)
3. Emigration (PMNs move through vessel walls)
4. Migration (PMNs move to injury tissues via chemotactic mediators)
5. Principal role is wound decontamination by phagocytosis
6. Macrophage Organization
   2 to 6 days post injury
7. Prompt formation of granulation tissue

Question 3

Proliferative Phase

Answer 3

1. Making granulation tissue by Fibroblasts and endothelial cells, orchestrated by FGF, IGF-1, PDGF
2. Fibroblasts start collagen production on the third day
   Days 3-7 are peak
   Starts as Type III—>Type I as wound matures (disorganized to organized)
   Transforms granulomatous tissues —>granulation tissues
3. Endothelial cells drive angiogenesis
   Starts 48-72 hours post injury
4. Epithelium Cells migrate from wound edges 0.5-1mm per day using fibrin clot until epithelial seal created
   In primary intention healing, epithelial seal forms in 21-28 hrs

Question 4

Maturation Phase

Answer 4

1. Begins 5-7 days after injury
2. Initially mostly fibronectin and hyalauronic acid, progresses to larger collagen bundles resulting in conversion of granulation tissue to connective tissue
3. The epithelial seal becomes the stratified squamous epithelium during this phase to protect from bacterial invasion
4. Epithelial barrier forms 36-42 hours after suturing and is characterized by a significant increase in wound strength

Question 5

4 zones of bone infection i order of increasing pathology

Answer 5

1. stimulation
2. irritation
3. contamination
4. infection

Question 6

What zone contains increased bone density and thickened trabeculae in osteitis

Answer 6

Stimulation

Question 7

What zone is PA/A seen in

Answer 7

Zone of irritation