2. Principles of Healing

Question 1

What are the phases of wound healing?

Answer 1

1. inflammatory phase
2. proliferative phase
3. maturation phase

Question 2

what are some mechanisms of wound repair?

Answer 2

• CT deposition
• epithelialization
• contraction

Question 3

what is the inflammatory phase characterized by/

Answer 3

hemostasis and inflammation –> stabilize the wound thru clot formation

Question 4

What is the first response cell in the inflammatory phase? what is the secondary response cell?

Answer 4

platelets- 1st response cell

neutrophils- 2nd response cell

Question 5

what cell type stimulates fibroblasts (collagen) and angiogenesis?

Answer 5

TNF

Question 6

what is the most essential cell for wound healing?

Answer 6

macrophages

inflammatory phase

Question 7

what unique things occur in the proliferative phase?

Answer 7

epithelization
angiogenesis
collagen deposition

Question 8

describe the orientation of collagen in the proliferative phase vs. the maturation phase.

Answer 8

collagen is oriented randomly in the proliferative phase compared to being more organized in the maturation phase

Question 9

in which phase does wound contraction occur?

Answer 9

maturation phase

Question 10

what is the time scale for each phase of healing?

Answer 10

inflammatory phase- 3 days
proliferative phase- 2 wks
maturation phase- a few weeks to a year

Question 11

what is the relationship of tissue thickness compared to tensile strength?

Answer 11

(inversely related) - collagen is unorganized and tissue is thick (tensile strength is low) but as maturation phase occurs, collagen becomes more organized and tensile strength increases

Question 12

what is the most important factor that affects wound healing?

Answer 12

blood supply

Question 13

what are the guiding principles of wound healing?

Answer 13

• vascular perfusion
• bacterial balance
• nutritional balance
• control contributing factors

Question 14

what is closure by primary intention?

Answer 14

side to side closure of the wound with sutures

*reapproximation of skin edges

Question 15

what is closure by secondary intention?

Answer 15

wound is left open to granulate to closure

Question 16

what is delayed primary closure?

Answer 16

wound is left open for a period of time and then primarily closed

Question 17

what is the primary event in a primary intention closure?

Answer 17

CT deposition

no contract, no epithelization

Question 18

what is the primary event in a closure by secondary intention?

Answer 18

contraction

yes CT deposition, and some epithelization

Question 19

what is the primary event in a partial thickness wound (very superficial)?

Answer 19

epithelization

no contract, no CT deposition

Question 20

what is the name of the scar that extends beyond the boundary of the original skin injury?

Answer 20

keloid

Question 21

what is the name of the scar that is within the boundary of the original skin injury?

Answer 21

hypertrophic scar

Question 22

what areas of the body are susceptible to keloid?

Answer 22

sternum, deltoid area, upper back have increased susceptibility bc they have elevated levels of muscle and skin tension

Question 23

what is the recurrence rate of keloid?

Answer 23

50%