Tissue Repair

Question 1

Is inflammation a specific or nonspecific response?

Answer 1

Non-specific

Question 2

What happens during inflammation?

Answer 2

Blood vessels to the area dilate

Increase in capillary permeability

Phagocytic cells move towards area

Histamine released

Question 3

What are the symptoms of inflammation?

Answer 3

•Redness
•Heat
•Pain
•Swelling
•Loss of function

Question 4

How is inflammation cell debris removed?

Answer 4

Following inflammation cell debris will be removed by phagocytic cells and wound
healing can occur.

Question 5

Do Labile Cells regenerate well?

Answer 5

Yes!

Labile Cells regenerate best (e.g. skin, lining of GI tract, blood forming tissue)

Question 6

Do stable cells repair easily?

Answer 6

Stable Cells have a lower turnover but can produce new cells e.g. hepatocytes (liver),
osteoblasts (bone)

Question 7

Do permanent cells repair easily?

Answer 7

No!

Permanent Cells are incapable of producing new cells (e.g. mature nerve cells, cardiac muscle cells)

Question 8

What are the three stages of wound healing?

Answer 8

1.Contraction of Wound
2.Tissue Repair
3.Tissue Regeneration

Question 9

What is the difference between Repair & Regeneration?

Answer 9

Regeneration - Replacement of damaged tissue by identical cells e.g. if epithelial basement membrane not damaged. No scarring will occur

Repair - If wound is deeper (past basement membrane) there will be both an epithelial and a connective tissue response (granulation tissue). Scarring will occur

Question 10

If the epithelial basement is not damaged will scarring occur?

Answer 10

No

Question 11

If the wound goes past the basement layer will scarring occur?

Answer 11

Yes

Question 12

What phase is this?

Answer 12

Inflammatory phase

Question 13

What phase is this?

Answer 13

Maturation Phase

Question 14

What is the first step of wound healing?

Answer 14

•Wound fills with blood

•Epithelial Cells separated from each other and the basement membrane

Question 15

What is the second step of wound healing?

Answer 15

•Cell division occurs
•Macrophages, Fibroblasts and myofibroblasts are attracted to the injury site
•New blood vessels develop
•Blood clot is phagocytosed
•Extracellular Matrix deposited

Question 16

What is the third step of wound healing?

Answer 16

•Dividing epithelial cells displace clot
•Basement membrane is secreted
•Macrophage and fibroblast numbers decrease

Question 17

What is the 4th and final step of wound healing?

Answer 17

•Wound is healed
•Cell division restores epithelial thickness
•Extra granulation capillaries are absorbed

Question 18

What happens in the primary intention healing?

Answer 18

Primary Intention - close edges, minimal tissue loss, minimal cell division required, little or no scar

Question 19

What happens in the secondary intention healing?

Answer 19

Secondary intention – edges far apart, large tissue loss, extensive cell division,
connective tissue response, scar formation

Question 20

Name some of the ways that influence wound healing

Answer 20

1.Blood Supply – avascular or ischaemic areas heal poorly

2.Infection – delays repair, increases granulation tissue, inflammation & scarring

3.Size of Wound – large wound takes longer to heal

4.Type of Wound – blunt or sharp, position

5. Ionising Radiation – damages blood supply – allow scar formation before radiotherapy
6. Foreign Body in Wound – delays healing
7. Movement – excessive movement before tensile
   strength developed delays healing
8. Age - Increased healing in younger people
9. Poor Nutrition – vitamin C needed to produce collagen,
   zinc deficiency slows healing, adequate protein intake
   needed
10. Other Factors – chronic disease, corticosteroid therapy impairs protein synthesis