PATH: Acute Inflammation Flashcards
What is the general definition of inflammation?
The reaction of the body to injury in vascularized tissue that brings cells and molecules of host defense from the circulation to sites where they are needed
What are the physiologic functions of inflammation?
Elimination of organism initially responsible for cell injury and consequences of the injury
What are the three major components of acute inflammation?
Increased blood flow (hyperemia), Increased microvascular permeability allowing escape of proteins and cells, and Emigration, accumulation, and activation of leukocytes
What is the physiologic function of edema?
Increased fluid in the tissue dilutes the offending agent, allowing inflammatory cells to attack and destroy it
What leukocyte is the major mediator of acute inflammation?
Neutrophils
What are some examples of harmful acute inflammation?
Acute respiratory distress syndrome,asthma, acute transplant rejection, glomerulonephritis, septic shock, lung abcess
True or False: All inflammation has infection as a source
False- not all inflammation is due to infection
What are the 4 Cardinal signs of acute inflammation
Calor (heat), Rubor (redness), Tumor (swelling), Dolor (pain)
What is the mechanism of increased vascular permeability in acute inflammation?
Immediate response- Formation of gaps between endothelial cells of venules (due to endothelial cell contraction) mediated by histamine, bradykinin, and leukotrienes; Delayed response- cytoskeletal changes of endothelium resulting in contraction mediated by cytokines IL-1, TNF, IFN-gamma; injury to endothelium; increased transcytosis
What is the leukocyte’s response in acute inflammation?
Margination, rolling, adherance, transmigration, chemotaxis, activation, phagocytosis, release reaction
What causes margination of leukocytes?
Vasodilation results in stasis of blood and displacement of leukocytes to the periphery
What is the mechanism by which leukocytes roll and adhere to the endothelial wall?
The leukocytes roll along the vascular wall through low affinity, transient attachment to endothelium via selectins and ligands; adhesion occurs through endothelial ligands (VCAM-1, ICAM-1) to integrins which are stimulated to a high-affinity state via chemokines
Where does transmigration/ diapedesis occur? What is the mechanism?
Post-capillary venules; Via PECAM-1/ CD31 interaction and local collagenases
List several mediators of acute inflammation.
HIstamine, serotonin, lysosomal enzymes, plasma proteins (complement system, kinin system, coagulation system), arachidonic acid metabolites, platelet activating factor, cytokines, nitric oxide
Which components of the complement system are especially inflammatory?
Anaphylatoxins C3a and C5a
