Inflammation

Question 1

Purpose of Inflammation

Answer 1

• Destroy
• Dilute
• Isolate healthy cell from injured
• Initiate repair- fibrosis/ regeneration

Question 2

Sequence of events in an inflammatory reaction

Answer 2

1) Dilation of small vessels
2) Increased permeability of microvasculature, edema
3) Recruitment of leukocytes to accumulate in injury atea

Question 3

What is a chemical mediator

Answer 3

Substance released by an injured or activated cell to co-ordinate inflammatory response

Question 4

Action of chemical mediators

Answer 4

Stimulate release of other mediators. These cascades pprovide mechanisms for amplifying or counteracting the initial action of a mediator.

Question 5

Exudate

Answer 5

Protein rich fluid which leaks through gaps in epithelial walls of vessels during inflammation, also due to stasis

Question 6

Transudate

Answer 6

Low protein and cell content fluid, due to decreased colloid osmotic ressure

Question 7

Oedema

Answer 7

An excess of watery fluid collecting in the cavities or tissues of the body.

Question 8

Origin and action of Nitric Oxide (NO)

Answer 8

• Produced by endothelial cells, macrophages and macrophages
• Vascular smooth muscle relaxation and vasodilation
• Kill microbes in activated macrophages
• Counteract platelet adhesion, aggregation and degranulation

Question 9

Vasoactive amine, example and action

Answer 9

• Histamine
• Vasodilation and venular endothelial cell contraction, junctional widening; released by mast cells, basophils, platelets in response to injury (trauma, heat, cold)

Question 10

Mechanisms causing vascular leakiness

Answer 10

Histamines, bradykinins, leukotrienes.

Question 11

How does chemotaxis work?

Answer 11

Leukocytes follow chemical gradient to site of injury
-Soluble bacterial products
-complement components
-cytokines
-leukotrienes
Chemotactic agents bind surface receptors including calcium mobilisation and assembly of cytoskeletal contractile elements

Question 12

Leukocyte activation

Answer 12

Prepare AA metabolites from phospholipids
Prepare for degranulation and release of lysosomal enzymes (oxidative burst)
Regulate leukocyte adhesion molecule affinity as needed

Question 13

Cell- derived chemical mediators

Answer 13

Preformed, sequesterd and released (serotonin, histamine), or newly synthesized (prostaglandins, ROS, cytokines etc.)

Question 14

Plasma derived chemical mediators

Answer 14

• Complement system
• Kinin system
• coagulation/ fibrinolysis system

Question 15

Action of kinin system

Answer 15

• Vascular permeability
• Arteriolar dilation
• Non-vascular smooth muscle contraction
• Pain
• Rapidly inactivated by kininases
• Intimate association with clotting pathway

Question 16

Prostacyclin

Answer 16

Vasodilation

Question 17

Thromboxane

Answer 17

Vasoconstriction

Question 18

Leukotrienes

Answer 18

Chemotaxins, vasocontrictors, increase vascular permeability and bronchospasm

Question 19

Platelet Actvating Factor (PAF)

Answer 19

Derived from cell membrane phospholipid, causes vasodilation, increased vascuar permeability, increases leukocyte adhesion (integrin conformation)

Question 20

Cytokines

Answer 20

Proteins- act via specific receptors, message to modulate cell function.
ILs, TNFs and IFNs in inflammation
Increase endothelial cell adhesion molecule expression- activate and aggregate leukocytes.

Question 21

Mechanisms to inhibit cytokine driven inflammation

Answer 21

Reduce cytokine producing cells

• Inhibitory cytokines
• Inhibitors of signal transduction
• Gene expression regulators
• Reduce circulating cytokines
• Block receptors

Question 22

Side effects of inflammation

Answer 22

Fever, anorexia, muscle degradation, hypotension, thrombus (cytokines)
Leukocytosis (elevated white blood cell count)