Wound Healing Flashcards

1
Q

Embryonic Stem Cells

A

Pluripotent; isolated from blastocysts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

PDGF, FGF, VEGF-A bind GF-R’s on endothelial cells to induce vascular formation by

A

Endothelial proliferation

Recruitment of pericytes

Deposition of ECM proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What occurs during the hemostasis phase of wound healing

A

Vasospasm → relaxation

Platelets aggregate to expose collagen and a network of fibrin forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Repair

A

Replacement of injured tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the arrangement of blood vessels in granulation tissue

A

Arranged perpendicular to fibrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Growth factors and cytokines involved in angiogenesis

A

VEGF, angiopoietin, FGF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Permanent Cell - Non-Dividing Cell

A

Have left the cell cycle and cannot undergo mitotic division in postnatal life

_________________________

Neurons, Cardiac and Skeletal Muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mechanism of wound healing by primary intention

A
  • Simple Incision
  • Sutured incision with acute inflammatory response (2-7 days)
    • Redness and swelling
    • Zone of acute inflammation; formulation of granulation tissue
  • Healing Incison
    • Epithelial proliferation and repair
    • Maturing fibrous granulation tissue
  • Linear fibrous scar (6-12 months)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mechanism of wound healing by second intention

A
  • Ragged, dirty or infected wound (2-3 days)
    • Necrotic slough
    • Acute inflammation
  • Phase of rapid proliferation of vascular granulation tissue (1-2 weeks)
    • Slough and scab
    • Epithelial proliferation
    • Vascular granulation tissue
    • Zone of hyperemia
  • Phase of granulation tissue maturation and wound contraction (3-6 weeks)
    • Fibrous granulation tissue beginning to contract, pull wound edges closer
    • Hyperemia
  • Healed wound
    • Pale depressed scar with puckering
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The proliferation phase of wound healing occurs when? And can last for how long?

A

3-7 days

3-4 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Quiescent - Stable Cells

A

Low level of replication; undergo rapid division in response to stimuli. Capable of reconstructing the tissue of orgin

_________________________

Smooth muscle, fibrocytes, vascular endothelial cells, chondrocytes, osteocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Collagen

A

Triple helices with lots of cross linkage providing tensile strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Characteristics of epithelialization

A

Proliferate at denuded surfaces

Must disassemble connections to basement membrane and neighboring cells

Must express surface receptors that bind ECM

Regulated by contact inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tissues ability to return to normal depends on

A

Retention of ECM structural framework

Regenerative capacity of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Myofibroblasts

A

Form within wounds in response to TGF-beta

Increase with time and severity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Proud Flesh

A

Hypertrophic scar - excessive granulation tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

T/F- Capillaries in granulation tissue are sturdy.

A

False

________________

Capillaries are fragile and bleed easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When does healing begin?

A

Immediately after a wound develops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Process of degradation during inflammation phase of wound healing

A

Leukocytes clean up cell debris from the injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Wound

A

Injured tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Tensile strength is diminished in what type of wound healing?

A

Secondary intention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Growth factors and cytokines involved in collagenase secretion

A

PDGF

FGF

TNF

TGF-beta inhibits

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Growth factors are required for cellular

A

Proliferation

Differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Angiogenesis

A

Formation of new blood vessels from existing ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

T/F: Proliferation phase of wound healing increases with age and disease.

A

False

_____________________

decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Growth factors and Cytokines involved in fibroblast migration/ replication

A

PDGF

EGF

FGF

TGF-beta

TNF

IL-1

27
Q

Fibroplasia

A

Migration and proliferation of fibroblasts

28
Q

Extracellular Matrix consists of

A

Collagen

Elastin

Fibronectin

Laminin

29
Q

What phase of wound healing is required for return of tensile strength

A

Maturation

30
Q

TGF-Beta

A

Produced by platelets and leukocytes

Important for fibroblast migration and proliferation, and collagen/ECM protein synthesis

31
Q

Epithelialization

A

Regeneration of epithelium

32
Q

Fibrosis

A

Scar formation by connective tissue remodeling

33
Q

Microscopically, what is found at the center of the wound during degradation

A

Dead cells

Leukocytes

Cytokines

Serum/clotting proteins

ECM substances

34
Q

Conditions that may cause impaired wound healing

A

Tension on a tissue

Prolonged inflammation

Disorders in collagen synthesis

Poor blood supply

Impaired ability of cellular regeneration

35
Q

Factors that favor fibrosis

A

Severe and prolonged tissue injury

Loss of tissue framework

Large amounts of exudate/inflammation

Lack of renewable cell populations

36
Q

Wound contraction is mediated by

A

Myofibroblasts

37
Q

Fibrous Connective Tissue

A

Dense accumulation of fibroblasts and collagen

With time, collagen becomes more densely packed

Persists for years

38
Q

What occurs during the proliferation phase of wound healing?

A

Regeneration of tissue

Granulation tissue formation

Stem cells influced by cytokines/growth factors

Fibroblasts proliferate to fortify the wound → collagen deposition

39
Q

Wounds that can be healed by second intention

A

Gaping wounds

Septic wounds

Foreign bodies

Wound with delayed healing processes

40
Q

Granulation Tissue

A

Distinctive arrangement of connective tissue fibers, fibroblasts and blood vessels

41
Q

What occurs during the inflammation phase of wound healing?

A

Cardinal signs seen

ECM components are chemotactic

Degradation

Leukocytes secrete chemotactic and growth factors → proliferation phase

42
Q

Growth factors and cytokines involved in monocyte chemotaxis

A

Chemokines

TNF

PDGF

FGF

TGF-beta

43
Q

Mechanism of angiogenesis

A
  1. Proteolysis of ECM
  2. Migration and chemotaxis
  3. Proliferation
  4. Lumen formation, maturation and inhibition of growth
  5. Increased permeability through gaps and transcytosis
44
Q

Phases of cutaneous wound healing

A

Hemostasis

Inflammation

Proliferation

Maturation

45
Q

Proliferation phase of wound healing is limited by

A

Proliferative potential of cell types involved

46
Q

Consequences of fibrosis

A

Loss of functional parenchymal tissue

Alteration of physical properties of tissue

47
Q

What occurs during the maturation phase of wound healing?

A

Remodeling of granulation tissue, maturation of fibrosis and wound contraction

Re-establishment of cell interactions

Vascular regression

48
Q

Labile - Continuously Dividing Cells

A

Proliferate throughout life, replacing those cells that are destroyed

_____________________________

Epithelial cells of liver, kidney, lung, pancreas, skin, mucous membranes

49
Q

T/F: If inflammation is excessive, it can reduce healing.

A

True

50
Q

Wounds that can be healed by primary intention

A

Wounds with opposed edges

51
Q

Role of extracellular matrix in regeneration and repair

A

Liver regeneration with restoration of normal tissue after injury requires intact cellular matrix

If matrix is damaged the injury is repaired by fibrous tissue deposition and scar formation

52
Q

Wound Contraction

A

Normal part of maturation phase

Can be bad when connective tissue contracts and place tension on surrounding tissues

May immobilize or deform tissue

53
Q

Growth factors and cytokines involved in collagen synthesis

A

TGF-beta

PDGF

54
Q

What induces fibroblasts to synthesize collagen?

A

Growth factors

55
Q

Important source for epithelial regeneration

A

Stem Cells

56
Q

The inflammation phase of wound healing occurs in what time frame

A

24-96 hours

57
Q

Growth factor mechanism

A

EGF binds receptors on epithelial cells → activates MAPK → induces G0 phase cell cycle

58
Q

Growth factors and cytokines involved in keratinocyte replication

A

HB-EGF

FGF-7

HGF

59
Q

Maturation phase of wound healing occurs when and can last for how long?

A

Begins 3-4 weeks after injury

Can last for years

60
Q

Results of the hemostasis phase of wound healing

A

Reduced blood loss

Binds edges of wound together

Initiate angiogenesis - PDGF, TGF-Beta

61
Q

Describe the arrangement of fibroblasts and connective tissue in granulation tissue

A

Grow parallel to the wound surface

62
Q

Tissue Stem Cells

A

Not pluripotent - restricted lineage specific differentiation capacity

Bone marrow - hematopoietic and mesenchymal cells

Skeletal muscle “satellite cells”

63
Q

Matrix Metalloproteinases

A

Important for degrading the ECM