Acute Inflammation 2 Flashcards
What is inflammation of the: 1. peritoneal cavity 2. meninges 3. appendix 4 lungs 5. pleural cavitiy called?
- peritonitis
- meningitis
- appendicitis
- pneumonia
- pleurisy
most follow rule ‘structure’-itis but there are some exceptions (e.g. 4&5)
What do neutrophils do?
They’re mobile phagocytes (recognise foreign antigen, move towards it by chemotaxis, adhere to organism).
They have granules containing oxidants (e.g. hydrogen peroxide) and enzymes (e.g. protases) which they release to destroy foreign antigens.
What is chemotaxis?
Neutrophils detect chemicals released by foreigners and move towards them by move up the concentration gradient on the chemicals.
What happens to neutrophils when they release the contents of their granules?
Neutrophils die.
This produces pus (mixture of fluid, bits of cells, organisms, endogenous proteins)
Name two plasma proteins involved in the inflammatory response.
Fibrinogen and immunoglobulins.
What would happen if the pus extends onto other tissues?
Inflammation would be progressed.
What are the role of immunoglobulins in inflammation?
Immobilise specific antigens - humour immune response.
What is the role of fibrinogen in inflammation?
It is a coagulation factor. It cleaves and polymerises to form fibrin which clots the exudate localising the inflammatory response.
Give examples of mediators in acute inflammation.
Molecules on endothelial cell surface membrane.
Molecules released from cells.
Molecules in the plasma.
Give examples of the collective effects of mediators.
Vasodilation Increased permeability Neutrophil adhesion Chemotaxis Itch and pain
** Give examples of cell surface mediators.
ICAM-1 - helps neutrophils stick
P-selectin - interacts with neutrophil surface
Why is histamine released during inflammation?
Mast cell degranulation is a component of inflammation and histamine is contained within these granules.
Molecules released from cells: histamine
preformed in mast cells besides vessels, platelets, basophils
released as result of local injury, IgE mediated reactions
Causes vasodilation, increased permeability
acts via H1 receptors on endothelial cells.
Molecules released from cells: 5-hydroxytryptamine (serotonin)
Preformed in platelets
Released when platelets degranulate in coagulation
Causes vasoconstriction
Molecules released from cells: prostaglandins (arachidonic acid metabolites via lipoxygenase pathway)
Released from many cells (endothelium + leukocytes)
Many promote histamine effects and inhibit inflammatory cells
Thromboxane A2 promotes platelet aggregation and vasconstriction - opposite effect of PGD2, PGE3 etc.
Molecules released from cells: leukotrienes (arachidonic acid metabolites via cyclo-oxygenase pathway)
Released from neutrophils especially
Vasoactive - dynamic effect on vessels to increase permeability and constrict smooth muscle
Molecules released from cells: omega-3 polyunsaturated fatty acids
Decrease synthesis of arachidonic acid derived inflammatory mediators
Molecules released from cells: platelet-activating factor (PAF)
Released from cell membranes of activated inflammatory cells
Reduces permeability by enhancing platelet degranulation at site of injury
Molecules released from cells: cytokines and chemokines (e.g. TNFalpha, IL-1)
Small molecules produced by macrophages, lymphocytes, endothelium in response to inflammatory stimuli
Attract inflammatory cells
Molecules released from cells: nitric oxide (NO)
Released by various cells
Smooth muscle relaxation, anti-platelet, regulates leukocyte recruitment to inflammatory focus