Class 2- Cellular Injury, Inflammation, and Wound Healing

Question 1

Describe the three types of cellular injury

Answer 1

1. Reversible
2. Apoptosis and Programmed Cell Removal
   
   • “peaceful” cell death
3. Necrosis
   
   • cell death
   • cause inflammation

Question 2

Mechanisms of Cellular Injury: Free Radical/ Reactive Oxygen Species (ROS)

Answer 2

• atom with unpaired electron
• causes “oxidative Stress”
• byproducts of normal metabolism but counteracted with antioxidants
• under stress antioxidants are overwhelmed

Question 3

What are the causes of Free Radical/ROS

Answer 3

• mutations
• protein breakdown or misfolding
• membrane damage

Question 4

Mechanisms of Cellular Injury: Hypoxic

Answer 4

• insufficient oxygen
• can be cognitive
• CP (from hypoxic injury near birth)

Question 5

Mechanisms of Cellular Injury: Reperfusion Injury

Answer 5

• decreased oxygen perfusion (Ischemia)
• causes inflammation and free radical release
• occurs in brain or heart

Question 6

Mechanisms of Cellular Injury: Chemical Injury

Answer 6

• drugs
• asbestos
• lead
• mercury (brain development)
• CO

Question 7

Mechanisms of Cellular Injury: Physical Agents

Answer 7

• mechanical forces
• extreme temperature
• electrical forces

Question 8

Other Mechanisms of Cellular Injury

Answer 8

• atmospheric pressure changes
• radiation
• environment (noise, sunlight)

Question 9

Four Results of Cellular Injury

Answer 9

1. mitochondrial damage (deceasing ATP)
2. Cell membrane damage (Na+/K+ pump, increased water, Ca++ entry)
3. Ribosome Damage (protein folding)
4. DNA

Question 10

Systematic Manifestations of Cellular Injury

Answer 10

• fatigue
• anorexia
• increased troponin
• malaise
• increase LDH
• triggers inflammatory response
• fever
• increased CK

Question 11

Inflammatory Response to Cellular Injury

Answer 11

• second line of defence
• part of innate immunity
• rapid
• non-specific
• activated by cell injury or necrosis

Question 12

Goals of Inflammatory Response

Answer 12

• prevents infection
• prevents further damage to other tissues
• contains bacteria
• limits/controls inflammatory process
• initiates adaptive immune response
• initiates healing

Question 13

Five Local Manifestations of Inflammation

Answer 13

1. Pain
2. Swelling
3. Heat
4. Redness
5. Loss of Function

Question 14

Vascular Inflammatory Response

Answer 14

• blood vessel dilation
• increased vascular permeability
• fluid into tissues
• more viscous blood
• clotting

Question 15

Cellulr Inflammatory Response

Answer 15

• WBC adherence to capillary
• WBC diapedesis (squeeze through capillary walls)
• WBC to injury (emigration)
• chemotaxis
• phagocytosis

Question 16

What is Chemotaxis?

Answer 16

movement of a motile cell or organism, or part of one, in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance

Question 17

Exudate Inflammatory Response

Answer 17

• fluid
• RBC
• WBC
• tissue debris

Question 18

Acute Inflammatory Response

Answer 18

• neutrophils
• macrophages
• histamine

Question 19

Systematic Manifestation of Acute Inflammation: Leukocytosis

Answer 19

• increased number of leukocytes

Question 20

Systematic Manifestation of Acute Inflammation: Lymphadenitis

Answer 20

• enlarged lymph nodes

Question 21

Systematic Manifestation of Acute Inflammation: Elevated Plasma Markers

Answer 21

• erythrocyte sedimentation rate (ESR)

- C-reactive protein

Question 22

Describe Chronic Inflammation

Answer 22

• lasts over two weeks
• persistant irritant
• unsuccessful acute inflammatory response
• long-term
• self-perpetuation
• debilitating
• in phagocytic cells neutrophils die and lymphocytes are activated
• can further injure cells and delay healing
• fibroblasts and scar tissue form causing loss of function
• risks of cancer, CAD etc.

Question 23

Systemic Manifestations

Answer 23

• low fever
• malaise
• fatigue
• anorexia
• leukocytosis
• lymphadenopathy
• increased ESR
• Increased C-reactive protein
• spleen hyperplasia
• anemia
• pain
• activity intolerance
• depression
• insomnia
• weight loss

Question 24

Phase One of Healing

Answer 24

Inflammation

• neutrophils and macrophages clean injured area
• blood clot acts as scaffold

Question 25

Phase Two of Healing

Answer 25

Proliferation and New Tissue Formation - fibroblasts secrete collagen and growth factors - new epithelial cells granulation of tissue

Question 26

Phase Three of Healing

Answer 26

Remodelling and Maturation - scar tissue formation - scar remodelling