Chapter 5 - Injury repair and aging

Question 1

Are stem cells found in epithelial, connective, or both?

Answer 1

both

Question 2

Which stem cell replaces lost epidermal cells?

Answer 2

basal cells

Question 3

Which stem cell replaces lost dermal cells?

Answer 3

mesenchymal cells

Question 4

Which heals quicker - incision or abrasion?

Answer 4

incision

Question 5

What is the first stage in the regeneration of skin after an injury?

Answer 5

Mast cells trigger an inflammatory response (mast cell activation)

Question 6

What is the second stage in the regeneration of skin after an injury?

Answer 6

scab/blood clot restricts the entry of additional microorganisms and stops the bleeding
cells of the stratum basale undergo rapid cell divisions and migrate to the edges of the wound to replace the missing epidermal cells. Macrophages patrol the damaged area of the dermis, destroying debris and pathogens by phagocytosis

Question 7

What happens if the wound occupies an extensive area or involves a region covered by thin skin?

Answer 7

dermal repairs must be underway before epithelial cells can cover the surface

Question 8

What is GRANULATION TISSUE?

Answer 8

combination of blood clot, fibroblasts, and extensive capillary network to repair the dermis

Question 9

What is the 3rd stage of regeneration of the skin after an injury?

Answer 9

(1 week later) scab is undermined by epidermal cells (produced by fibroblast activity). Fibrin clot is breaking up and phagocytosis is basically over

Question 10

What is the 4th stage of skin regeneration after an injury?

Answer 10

epidermis is complete, scab has been shed. Shallow depression marks the injury site but fibroblasts in the dermis continue to create scar tissue to elevate it (several weeks later)

Question 11

What happens when scar tissue formation continues beyond the requirements of tissue repair?

Answer 11

thick, raised scar tissue - keloid - is formed. keloid is covered by an epidermal surface

Question 12

When we age, the number of dendritic cells decreases to ___% of levels seen at maturity

Answer 12

50%

Question 13

Vitamin D3 production decreases about __%

Answer 13

75

Question 14

Older individuals do not tolerate the summer heat as much as when they were young and they are more prone to heat related illness. What accounts for these changes?

Answer 14

blood supply to the dermis has decreased and merocrine sweat glands have become less active, making it harder for the elderly to cool themselves

Question 15

Why does hair turn white or gray with age?

Answer 15

decreased melanocyte activity

Question 16

What is the purpose of the rule of nines?

Answer 16

to estimate the surface area of an adult affected by a burn

Question 17

Anterior trunk

Answer 17

18%

Question 18

Anterior head and neck

Answer 18

4.5%

Question 19

Anterior thighs, legs, and feet

Answer 19

18%

Question 20

Anterior shoulders, arms, forearms, and hands

Answer 20

9%

Question 21

Perineum

Answer 21

1%

Question 22

What are the 3 major types of skin cancer

Answer 22

-basal cell carcinoma
-squamous cell carcinoma
-malignant melanoma

Question 23

The dermis develops from the ..?

Answer 23

mesoderm

Question 24

The endodermis develops from the..?

Answer 24

ectoderm

Question 25

4 phases of repair:

Answer 25

1. Inflammatory
2. Migratory
3. Proliferation
4. Scarring

Question 26

What are the 2 kinds of wound healing?

Answer 26

epidermal wound healing and deep wound healing