Inflammation part 1

Question 1

Acute inflammation

Answer 1

-vascular and cellular inflammatory reactions are mediated by chemical mediators that are derived from plasma proteins or cells in response to inflammatory stimulus

Question 2

Stimuli for acute inflammation

Answer 2

-microbes and toxins
-trauma
-physical and chemical agents
-tissue necrosis
-foreign bodies (eg.splinters)
-immune reactions (hypersensitivity reactions)

Question 3

Sequence of inflammatory events

Answer 3

1.inflammatory stimulus
2.release of mediators (histamine and cytokines)
3.Vasodilation
4. increased blood flow and volume leading to heat/redness=hyperemia
5.increased permeability= loss of fluid= edema (swelling and pain)
6. Increased viscosity of blood results in slowed blood flow=stasis
7. Neutrophil margination, rolling, adhesion &migration into the interstitial tissue
8. Phagocytosis

Question 4

Vascular changes during inflammation

Answer 4

-normal: plasma proteins and cells are kept in vessels and more in direction of blood flow
-inflammation: movement of plasma proteins and circulating cells move out of circulation and into site of infection

Question 5

Vasodilation during inflammation

Answer 5

-caused by histamine, prostaglandins, and NO
-results in arteriolar dilation, and increase in blood volume and opens of new capillaries

Question 6

Permeability vascular changes

Answer 6

-increased permeability (from increased endothelial gaps between cells)
- allows protein rich fluid to move into interstitium

Question 7

How are gaps between endothelial cells formed?

Answer 7

1.Histamine, bradykinin, leukotrienes cause endothelial contraction by reorganizing the cytoskeleton resulting in endothelial gaps
2.direct endothelial injury (necrotic processes such as toxins, and leukocyte mediated through free radicals and proteases) causing necrosis an detachment
3.increased transcytosis in venules induced by VEGF
4.leakage of new blood vessels

Question 8

Viscosity of blood

Answer 8

-loss of fluid results in concentration of cellular fraction of blood in capillaries and venules, which increases viscosity of blood and slower blood flow

Question 9

Hypoproteinemia and vascular permeability

Answer 9

-loss of protein from the plasma through endothelial leakage
>due to decrease in intravascular osmotic pressure and an increased osmotic pressure of the interstitial fluid

Question 10

Exudate

Answer 10

-same as high protein edema; cloudy
-always seen when you get gaps in endothelial cells

Question 11

Transudate

Answer 11

-low protein; clear or light yellow
-move through changes in hydrostatic pressure

Question 12

Ascites (transudate)

Answer 12

-low protein
-would not expect endothelial injury/gaps formed

Question 13

Acute severe diffuse fibrinous pleuritis

Answer 13

-acute because fibrin can be pulled apart, not many cross links

Question 14

Why does fluid exude?

Answer 14

-dilute injurious stimulus
-contain and isolate the process
-delivers antimicrobial substances (eg. Immunoglobulins)
-provides a meshwork for inflammation and repair