Lesson 4: Wound Healing and Growth

Question 1

When only the epidermis has been penetrated

Answer 1

Epidermal wound

Question 2

When the dermis has been penetrated

Answer 2

Deep wound

Question 3

A superficial burn that affects only the epidermis

Answer 3

First-degree burn

Question 4

Injury to epidermal layer

Answer 4

Cells in the stratum basale break off from the basement membrane, enlarge, and migrate across the wound. Individual cell migration stops when two epidermal cells meet one another.

Question 5

What are the phases of deep wound healing?

Answer 5

1. Inflammatory
2. Proliferation and Migration
3. Maturation and Remodeling

Question 6

What occurs during the first stage of wound healing?

Answer 6

Inflammatory phase

Fibrin and blood platelets form a blood clot (known as hemostasis). Damaged tissue causes inflammatory factor Histamine to be released, which in turn triggers vasodilation and an increase in the permeability of the blood vessels

Question 7

What occurs during the second phase of wound healing?

Answer 7

Proliferation and Migratory phase

Occurs two or three days later. Epithelial cells then migrate across the basal surface of the scab to connect the borders of the wound. Fibroblasts migrate along fibrin threads and secrete collagen to strengthen the clot and blood vessels grow back

Question 8

Delicate tissue that grows in the proliferation phase

Answer 8

Granulation tissue

Question 9

What happens after the granulation tissue forms?

Answer 9

Fibroblasts trigger the endothelial cells surrounding the wound to proliferate underneath the scab. Collagen fibers are deposited by fibroblasts in a random arrangement, and the blood vessels continue to grow

Question 10

What occurs during the third phase of deep wound healing?

Answer 10

Maturation and remodeling

Can last from 3 weeks to 6 months. Scabs slough off, collagen fibers become more organized, and fewer fibroblasts are present. Blood vessels are back to normal.

Question 11

The formation of scar tissue that does not have the same function as the original tissue

Answer 11

Fibrosis

Question 12

What are the differences between scar tissue and undamaged tissue?

Answer 12

Scar tissue - higher density of collagen, reduced elasticity, might not develop the same number and variety of accessory structure (sweat glands, hair follicles, etc), lighter color than surrounding skin

Question 13

Te skin is damaged by intense heat, radiation, electricity, or chemicals. The damage results in the death of skin cells which can lead to dehydration, electrolyte imbalance, and renal and circulatory failure follow.

Answer 13

Burn

Question 14

What is the term called when burns are measured in terms of the size of the total surface area affected?

Answer 14

Rule of nines

Question 15

A superficial burn that affects only the epidermis. Red, painful, and swollen

Answer 15

First-degree burn, heals on their own within a few days

Question 16

Burn that goes deeper and affects both the epidermis and a portion of the dermis. Causes swelling and painful blistering

Answer 16

Second-degree burn, keep burn site clean and sterile to prevent infection, heals within several weeks

Question 17

Burn that fully extends into the epidermis and dermis. Destroys the tissue and affecting the nerve endings and sensory function

Answer 17

Third-degree burn, appear white, red, or black. Requires medical attention and will heal slowly without it

Question 18

Severe burn affecting the underlying muscle and bone, not usually painful (along with third-degree) because the nerve endings themselves are damaged.

Answer 18

Fourth-degree burn, full-thickness burns can’t be repaired by the body b/c the local tissues used for repair are damaged and require excision (debridement or amputation