Injury, Inflammation, & Healing

Question 1

What are the common mechanisms of cell injury?

Answer 1

Ischemia, infectious agents, immune, genetic, nutritional, physical factors, mechanical factors, psychosocial factors

Question 2

Adaptation

Answer 2

Persistent stress such as Weight lifting or muscle hypertrophy will lead to a healed cell

Question 3

Reversible cell injury (mild)

Answer 3

Such as a cut or broken bone will lead to a normal healed cell

Question 4

Reversible cell injury (severe)

Answer 4

cardiac ischemia, 3rd degree burn -> will lead to irreversible cell injury -> necrosis

Question 5

What is Necrosis

Answer 5

Traumatic cell death

Question 6

Apoptosis

Answer 6

Genetically programmed cell death

Question 7

Hypertrophy

Answer 7

Increase in size of cell and organ

Question 8

Hyperplasia

Answer 8

Increase in number of cells leading to increased organ size

Question 9

Atrophy

Answer 9

Reduced cell size and number, reduced size of organ

Question 10

Metaplasia

Answer 10

Change in cell morphology and function

Question 11

Phases of Healing

Answer 11

Injury -> inflammation -> proliferation -> maturation

Question 12

5 cardinal signs of inflammation

Answer 12

Erythema, Heat, edema, pain, loss of function

Question 13

Inflammation phase lasts?

Answer 13

Typically 1-6 days

Question 14

Proliferation phase lasts

Answer 14

3-20 days

Question 15

Maturation phase lasts?

Answer 15

9 days +

Question 16

Local signs of infection

Answer 16

Pain, tenderness, swelling, redness, warmth, bacterial, viral, respiratory (coughing sneezing) Digestive (vomiting, diarrhea)

Question 17

Systemic signs of infection

Answer 17

Fevers, chills, sweating, malaise, swollen lymph, weakness, headache, nausea

Question 18

Inflammation Phase - Vascular Response

Answer 18

Vasoconstriction (at injury) vasodilation (around injured tissues) Histamines, serotonin, bradykins, prostaglandin

Question 19

Inflammation Phase - Hemostatic Response

Answer 19

Clotting a thrombus formation

Question 20

Inflammation Phase - Cellular Response

Answer 20

Neutrophils, monocytes, and macrophages

Question 21

Proliferation Phase - Epithelization

Answer 21

Clot creating a barrier over the scab. Initiated within a few hours. Can vary with size of wound

Question 22

Proliferation Phase - Collagen Production

Answer 22

Fibroblasts create collagen, fibroblasts align perpendicular to capillaries. Keep combining to form collagen fibers

Question 23

Granulation Tissue

Answer 23

Granulation tissue increases fibrin decreases. Tensile strength is low. Contains capillaries, fibroblasts, myofibril-blasts

Question 24

Proliferation Phase Wound Contracture

Answer 24

Begins 5 days to 2 weeks. Edges of wound are pulled together. Muofibroblasts primarily responsible

Question 25

Primary Intention

Answer 25

Straight injury (typically surgical) can be closed easily and create a fine scar

Question 26

Secondary intention

Answer 26

Jagged or rounded injury will heal from the bottom. Takes longer to heal and will lead to a larger scar

Question 27

Neovascularization

Answer 27

Development of new blood supply. Important to a PT because too much stress = damage, too little stress = excess adhesion & contracture

Question 28

Maturation Phase process

Answer 28

Change occurs in size, form, and shape of scars, maximize strength of healing tissues, longest phase of healing, scar becomes paler

Question 29

Collagen and Maturation Phase

Answer 29

Balance between synthesis and lysis. Type 1 collagen synthesized

Question 30

Complications of Healing

Answer 30

Infection, ulceration, dehiscence, keloid development, adhesion

Question 31

Keloid scar

Answer 31

Grow outside the line of injury

Question 32

Hypertrophic scar

Answer 32

Do not grow outside of boundaries but are raised

Question 33

Acute inflammation

Answer 33

Resolution within a few weeks, neutrophils, minimal scarring

Question 34

Chronic Inflammation

Answer 34

Prolonged period of time (6+ months) neutrophils, macrophages, lymphocytes, create fibrosis scarring and granuloma formation

Question 35

Dysplasia

Answer 35

Abnormal cells (may indicate cancer)