Wound Healing Flashcards Preview

Foundations of Disease and Therapy > Wound Healing > Flashcards

Flashcards in Wound Healing Deck (32):
1

Granulation Tissue

Initial phase of repair; consists of fibroblasts secreting Type III collagen, capillaries, and myofibroblasts.

Characterized by:

  1. acute inflammation
  2. neovascularization
  3. edema

2

Causes of delayed wound healing

Infection, Vitamin C, Copper, or Zinc deficiency, or other causes such as foreign body, ischemia, diabetes, or malnutrition

3

Secondary Intention

Edges of wound are not brought together. Granulation tissue fills the defect, myofibroblasts then contract and form a scar

4

Fibrosis

Excessive deposition of collagen in tissue. Often triggered by macrophages and chronic inflammation 

5

When does repair occur

When regenerative cells are lost (i.e. deep skin cut) or when a tissue lacks regenerative capacity

6

stem cell location in skin

basal layer

7

Keloid

excess production of scar tissue that is OUT OF PROPORTION to wound; characterized by Type III Collagen. Affects African Americans in earlobes, face, and upper extremities

8

Steps of Repair by Connective tissue 

  1. Inflammation 
  2. Angiogenesis
  3. Migration and proliferation of fibroblasts
  4. Scar formation
  5. Connective tissue remodeling

9

Hypertrophic scar

excess production of scar tissue that is localized to wound

10

Permanent tissues

Lack regenerative potential. Healing must occur through fibrosis. Examples include myocardium, skeletal muscle, and neurons.

11

Labile Tissue

Possess stem cells that continuously cycle and regenerate the tissue. Examples include small and large bowel, skin, and bone marrow

12

Collagenase

Removes Type III collagen in granulation tissue and replaces it with Type I collagen; Requires Zinc cofactor!

13

TGF-beta

important fibroblast growth factor; also inhibits inflammation

14

stem cells in bone marrow and marker

hematopoietic stem cells; CD 34

15

Platelet-derived Growth Factor

growth factor for endothelium, smooth muscle, and fibroblasts

16

Steps of Cutaneous Wound Healing

  1. Inflammation (injury and formation of clot)
  2. Proliferation (granulation, re-epithelialization of wound surface)
  3. Maturation (ECM deposition, tissue remodeling)

17

Zinc

Cofactor for collagenase

18

Define Regeneration

replacement of damaged tissue with native tissue

19

Vascular endothelial growth factor (VEGF)

important for angiogenesis

20

Stem cell location in small and large bowel

mucosal crypts

21

Stable Tissue

Cells are normally quiescent, but can reenter cell cycle and regenerate when necessary. Examples include liver cells.

22

Define Repair

replacement of damaged tissue with a fibrous scar

23

Type III collagen

pliable material that is present in granulation tissue, embryonic tissue, uterus, and keloids

24

Tensile strength of scar

about 70-80% of strength of origninal tissue 

25

Scar

Pale, avascular, nearly acellular collagenous tissue with a few fibroblasts. Surface is covered by intact epithelium

26

TGF-alpha

epithelial and fibroblast growth factor

27

Vitamin C

Cofactor in hydroxylation of proline and lysine in procollagen residues; important for collagen formation

28

3 types of tissue based on regenerative capacity

Labile, Stable, and Permanent

29

Dehiscence

rupture of a wound; most commonly seen after abdominal surgery

30

Copper

Cofactor for lysyl oxydase, which cross-links lysine and hydroxylysine to form stable collagen polymers

31

Fibroblast growth factor

important for angiogenesis

32

Primary Intention

Would edges are brought together (as in suturing); leads to minimal scar formation