2.5 Wound Healing

Question 1

Regeneration

Answer 1

Replacement of damaged tissue with native tissue

Question 2

Labile Tissues

Answer 2

Constantly regenerating tissue that has stem cells that allows for complete regeneration of the tissue.

Question 3

Where are the stem cells in the small and large intestine?

Answer 3

Mucosal Crypts

Question 4

Where are the stem cells in the skin?

Answer 4

Basal layer

Question 5

Where are the stem cells in the bone marrow?

Answer 5

HSCs

Question 6

What is the marker of HSCs?

Answer 6

CD34

Question 7

Stable Tissues

Answer 7

Quiescent cells that can reenter the cell cycle and regenerate if necessary

Question 8

Permanent Tissues

Answer 8

Lack significant regenerative potential

Question 9

What are examples of permanent tissues?

Answer 9

• Cardiac
• Neural
• Skeletal Muscle

Question 10

Repair

Answer 10

Replacement of normal damaged tissue with a fibrous scar and it occurs in tissues that lack regenerative potential

Question 11

When will repair occur in labile or stable tissues?

Answer 11

When damage to the stems cells occurs, these tissues will regenerate with a fibrous scar

Question 12

What is the initial stage of repair?

Answer 12

Granulation

Question 13

What are the 3 components of granulation?

Answer 13

• Fibroblasts
• Capillaries
• Myofibroblasts

Question 14

What is the function of fibroblasts?

Answer 14

Deposition of type III collagen

Question 15

What is the function of capillaries?

Answer 15

Providing nutrients

Question 16

What is the function of myofibroblasts?

Answer 16

Contraction of the wound

Question 17

What will granulation tissue lead to?

Answer 17

Scar formation

Question 18

What happens to the collagen during scar formation?

Answer 18

Type III collagen is replaced with Type I collagen

Question 19

What removes Type III collagen?

Answer 19

Collagenase

Question 20

What is a cofactor for collagenase?

Answer 20

Zinc

Question 21

Primary Intention

Answer 21

Wound edges are approximated during healing and leads to minimal scar formation

Question 22

Secondary Intention

Answer 22

Wound edges are not approximated during healing and leads to granulation tissue filling in the wound, leading to future scar formation and contraction of the wound by myofibroblasts.

Question 23

What is the most common cause of delayed wound healing?

Answer 23

Infection

Question 24

What are some deficiencies that lead to delayed wound healing?

Answer 24

• Vitamin C deficiency
• Zinc deficiency
• Copper deficiency

Question 25

Dehiscence

Answer 25

Rupture of the wound. Most commonly seen after abdominal surgery.

Question 26

Hypertrophic Scar

Answer 26

They are characterized by deposits of excessive amounts of collagen I which gives rise to a raised scar.

Question 27

Keloid

Answer 27

Excess production of scar tissue that is grossly out of proportion with the tissue and are largely deposits of collagen III

Question 28

What populations are most susceptible for keloids?

Answer 28

African Americans