Week 1: Inflammation Response/ Wound Repair

Question 1

What is the goal of wound healing?

Answer 1

To restore the structural and functional integrity of the injured tissue

Question 2

What are the outcomes of wound healing?

Answer 2

Regeneration and resolution

Repair

Question 3

What is regeneration and resolution?

Answer 3

Returns tissue back to original structure and function

Question 4

What is repair?

Answer 4

Returns tissue structure but not function

Question 5

What are some tissues that undergo regeneration and resolution when damaged?

Answer 5

Corneal epithelium
Bone
Superficial skin

Question 6

What are some tissues that repair when wounded?

Answer 6

Heart, brain, retina

Question 7

What does wound healing begin with?

Answer 7

Acute inflammation

Question 8

What are the phases of wound healing?

Answer 8

Inflammation phase
Proliferative Phase
Maturation Phase

Question 9

When does the inflammatory phase occur?

Answer 9

Day 2-5

Question 10

When does the proliferative phase occur?

Answer 10

Day 5 to week 3

Question 11

When does the maturation phase occur?

Answer 11

Week 3 to year 2

Question 12

What happens in the inflammatory phase?

Answer 12

• Acute inflammatories send phagocytic cells and clotting factors to the damaged site:
• blood clots, bleeding stops
• destroys foreign agents
• Constriction of blood supply
• formation of scab
• Debridement: removing clots, microorganisms, red blood cells, and dead tissue cells. Prepares for tissue growth. Phagocytosis by macrophages.
• Edema dissipates after debridement.

Question 13

What happens in the proliferation phase?

Answer 13

• Granulation tissue develops (vascularized connective tissue full of macrophages)
• Angioblast proliferation (blood vessel growth)
• Fibroblast proliferation (collagen and extracellular matrix synthesis, also precursor for scar)
• Contraction ( Myofibroblasts gradually close wound)
• Epithelialization (Matrix Metalloproteinases remodel new collagen in wound. Cell differentiation occur when edges of wound meet.)

Question 14

What happens during the maturation phase?

Answer 14

Continued cellular differentiation (epithelium)
Scar remodeling, trying to make the scar smaller
Collagen becomes more organized
Granulation tissue becomes connective tissue
Can last up to 2 years.

Question 15

Local factors that affect wound healing

Answer 15

Size
Infection 
Location
Mechanical factors
Foreign bodies

Question 16

Leading cause of delayed wound healing

Answer 16

Infection

Question 17

Systemic factors affecting wound healing

Answer 17

Nutrition:
Protein- decreased collagen production
Vitamin C- inhibits collagen synthesis

Metabolic Diseases - Diabetes Type 2; any other disease that messes up processes
Vascularization disease - Atherosclerosis, arteriosclerosis, or varicose veins. Impairs blood flow
Hormones - Cortisol; specifically endogenous glucocorticoids (STRESS) are anti-inflammatory and slow healing

Question 18

4 examples of dysfunctional wound healing

Answer 18

Dehiscence
Ulceration
Keloid
Contracture

Question 19

Most common cause of dehiscence

Answer 19

Infection

Question 20

What is dehiscence? What can cause it?

Answer 20

Dysfunctional wound healing. The wound pulls apart at the suture line.
Deficient scar formation
-excessive strain 
-obesity
-infection

Question 21

What can cause an ulceration?

Answer 21

Inaquadate blood supply
Infection
Mechanical factors (bed sore)

Question 22

What is a keloid? Who has a higher incidence?

Answer 22

Excessive fibroblast growth. Dont have an “off switch” and will produce excess collagen matrix.

• African Americans get them more often.
• Doctors need to know if the patient has keloids for procedure purposes.

Question 23

What is a contracture? Does it have primary or secondary wound healing intentions?

Answer 23

Dysfuctional wound healing that has increased myofibril activity.
Burns increase the myofibril activity. It has secondary intention.
Burn victim would have this

Question 24

Injured tissues are repaired by regeneration of ___________ or by ___________ repair in which scar tissue is substituted for the ____________ of the injured tissue.

Answer 24

parenchymal cells; connective tissue; parenchymal cells

Question 25

True or false: | Scar tissue repairs the structure with functioning parenchymal cells.

Answer 25

False; it does not repair with functioning parenchymal cells.

Question 26

Repair is the replacement of destroyed tissue with _______

Answer 26

Scar tissue

Question 27

What is a scar primarily made of?

Answer 27

Collagen.

Question 28

What is primary intention wound healing? What happens?

Answer 28

Limited injury wound healing mostly associated with the epidermis. Would be a clean cut like a paper cut or surgical incision. Edges are in opposition. Able to close edges of the wound which provides greatest chance for regeneration. Provides minimal tissue loss. Fibrin clot from coagulation system and trapped platelets. Clot dissolves as healing progresses. Forms granulation tissue

Question 29

What is granulation tissue?

Answer 29

New tissue after injury that contains blood vessels. Activates angioblasts that create blood vessels to supply to injured area. Gradually replaces blood clot at injured site.

Question 30

What is secondary intention wound healing?

Answer 30

Wounds that require a great deal more tissue replacement. Open wound/ tissue loss Almost always getting repair healing. More likely to have scar. Only regain 80% of original tensile strength.

Question 31

How would skin heal faster if there is a scab?

Answer 31

Keep the scab moist. This keeps the fibrin clot moist and able to move easier. Less likely to scar

Question 32

What directly stimulates fibroblasts?

Answer 32

Macrophages stimulates fibroblast proliferation. Through transforming growth factor B into cytokines.

Question 33

What do matrix metalloproteinase (MMP) do?

Answer 33

They move through collagen to dissolve it where necessary to get where it needs to go.

Question 34

What part of the eye has regeneration?

Answer 34

Corneal epithelium

Question 35

What part of the eye undergoes repair?

Answer 35

Corneal Stroma, scar not clear. | Retina. Looses clarity from inflammation

Question 36

Describe wound healing abilities change with a young baby?

Answer 36

Inefficient chemotaxis: phagocytic cells don't move well (and neither do neonates!) Complement deficiency Antimicrobial peptide deficiency Limited biochemical barriers

Question 37

Describe wound healing abilities change with old age?

Answer 37

Reduced innate immune response: - Fewer cellular mediators - Diminished chemotaxis - Decreased phagocytotic activity Impaired inflammation: - Impaired metabolism and tissue perfusion - Medication effects Loss of regenerative ability: - Thinning of skin - Loss of subQ fat

Question 38

Describe pyogenic granuloma

Answer 38

Benign, vascular lesion Not infectious Not chronic Associated with trauma or a mild irritant More common in young Typically removed for comfort and cosmesis

Question 39

What type of cell gets to an injury the quickest?

Answer 39

Neutrophil