TISSUE REPAIR Flashcards

1
Q

Identify this pathologic repair process

accumulation of excessive amounts of collagen

remain within the confines of the original wound.

May regress spontaneously

Bundles of collagen fibers lie in a parallel arrangement

A

Hypertrophic scar

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

Identify this pathologic repair process

scar tissue grows beyond the boundaries of the original wound

Does not regress

Bundles of collagen fibers lie in a disorganized fashion

Frequently recurs after excision

A

Keloid

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

List 2 examples of stable tissues

A

parenchyma of liver, kidney, and pancreas

endothelial cells, fibroblasts, and smooth muscle cells

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

Which type of tissues/cells best fits the description given below?

can readily regenerate after injury as long as the pool of stem cells is preserved

A

Labile (continuously dividing) tissues

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

Special stain to demonstrate collagen

A

Masson’s Trichrome stain

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

See attached image. What is the underlying basis?

A

Exaggerated wound contraction

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

2 major mechanisms of liver regeneration

A
  1. Proliferation of residual hepatocytes
  2. Repopulation from progenitor cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name the localized tumor resulting from proliferation of fibroblasts, with very low metastatic potential

A

Desmoids (aggressive fibromatoses)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

List 1 word that best fits the description given below:

Fibrosis that develops in a tissue space occupied by an inflammatory exudate

A

Organization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which type of tissues/cells best fits the description given below?

Inability to proliferate in response to injury; terminally differentiated

A

Permanent tissues

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

Which type of tissues/cells best fits the description given below?

minimal proliferative activity in their normal state but capable of dividing in response to injury or loss of tissue mass

A

Stable tissues

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

List 3 examples of permanent tissues

A
  1. Neurons
  2. Cardiac myocytes
  3. Skeletal muscle cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

See the attached image and identify the abnormal pathologic repair process

A

Exuberant granulation (proud flesh)

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

Two mechanisms via which repair occurs

A
  1. Regeneration
  2. Scar (connective tissue deposition) formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List 3 examples of labile tissues

A

Bone marrow

Skin

GI tract

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

3 key differences between hypertrophic scars and keloids

A
17
Q

Identify the pathologic repair process shown in the attached image

Etiologic basis ?

A

Wound dehiscence

Secondary to mechanical stress - Vomiting, coughing, or ileus

18
Q

Most important mediator of fibrosis

A

TGF-beta

19
Q

List 6 key differences between healing by first and second intention

A

See attached table

20
Q

By when does wound strength reaches approximately 70% to 80% of normal?

A

Month 3

21
Q

By when does the wound acquire tensile strength approximately 10% of that of unwounded skin?

A

End of week 1

22
Q

Identify the timeline during which the following events are likely to occur in wound healing

increasing collagen deposition, regression of vessels, edema and leukocytic infiltrate

A

Week 2

23
Q

Identify the timeline during which the following event is likely to occur in wound healing

granulation tissue formation is at its peak

A

Day 5

24
Q

List 1 example of healing by first intention

A

healing of a clean, uninfected surgical incision approximated by surgical sutures

25
Q

List examples of healing by second intention

A

large wounds, abscesses, ulceration, and ischemic necrosis (infarction) in parenchymal organs

26
Q

How does zinc deficiency impair wound healing?

A

Zinc: ↑type III collagen; ↓tensile strength

27
Q

How does copper deficiency impair wound healing?

A

↓Copper: ↓cross-linking of collagen

28
Q

How does Vitamin C deficiency impair wound healing?

A

structurally weakened collagen due to lack of Vit C for hydroxylation of proline and lysyl residues and no cross linking

29
Q

How does corticosteroid administration affect wound healing?

A

Glucocorticoids –> inhibition of TGF-β production —->decreased fibrosis and collagen production —->weak scar

30
Q
  1. Identify this key event of the wound healing process
  2. When does it begin?
  3. When does it reach its peak?
A
  1. Granulation tissue
  2. Day 3
  3. Day 5
31
Q

Microscopic appearance of granulation tissue

A

proliferation of fibroblasts and new thin-walled, delicate capillaries (angiogenesis), in a loose extracellular matrix, with admixed inflammatory cells, mainly macrophages

32
Q

List 3 actions of TGF-beta in scar formation

A
  1. stimulates fibroblast migration and proliferation
  2. increased synthesis of collagen and fibronectin
  3. decreased degradation of ECM due to inhibition of metalloproteinases
33
Q

Which pathway ensures proper patterning of the newly formed vessels in angiogenesis?

A

Notch pathway

34
Q

List 4 mediators of angiogenesis

A

VEGF

FGF

PDGF

TGF-beta

35
Q

Role of VEGF in angiogenesis

A
  1. promotes vasodilation by stimulating the production of NO
  2. stimulates survival, migration and proliferation of endothelial cells
36
Q

First step in the tissue repair process

A

Formation of a fibrin clot

37
Q

What is the basis for the formation of contractures?

A

Excessive MMP activation - encourages migration of myofibroblasts at wound edges and scar tissue remodelling

38
Q
A