Acute and Chronic Inflammation Flashcards
What does the inflammasome do?
Recognizes dead cells, activates caspase-1 which activates IL-1 which triggers leukocyte recruitment
What is the key difference between TLR and Inflammasome??
TLR recognizes extracellular microbes (located in plasma mem) and the inflammasome recognizes products of dead cells and some microbes (located in cytoplasm)
What are the main chemical mediators that induce vasodilation?
Histamine and NO
What action causes increased vascular permeability?? What are two mediators of this?
Endothelial cell contraction
Histamine and Bradykinin
What is the cytokine that can stimulate histamine release?
IL-1
What are the functions of Bradykinin?
Causes vasodilation, increased permeability and pain
What causes transudate? How is it different from exudate?
Transudate is caused by osmotic/hydrostatic pressure imbalances. It results in fluid leakage due to hypocellular and low protein content. Low s.g.
Exudate is caused by an alteration in normal vessel permeability. Cellular and protein rich. High s.g. Fluid and protein leakage. Happens with inflammation.
Name the steps in leukocyte recruitment to an injury site.
Margination– leukocyte accumulation at periphery of vessels
Rolling– week and transient adhesions to endothelium
Adhesion– firm adhesion to endothelium
Transmigration– movement through endothelium to interstitium
Chemotaxis– movement towards injury site
What are the two types of adhesion molecules and the strength of their attachment?
Selectins– loose attachment to endothelial cells
Integrins– stable attachment to endothelium
What two cytokines increase endothelial cell ligand expression for integrin binding?
IL-1 and TNF (secreted by macrophages)
Definition of diapedesis. Chemokine that drives this action.
Movement of leukocytes through vessel wall
CD31 (PECAM1) on leukocytes and endothelial cells
Some examples of chemotactic factors.
Bacterial products, chemokines, complement, leukotrienes
What happens after leukocyte recruitment? Results of this.
Leukocyte activation
- phagocytosis
- intracellular destruction
- release of substances that destroy dead tissue and microbes
- more mediator production
Molecules that mediate recognition of microbe by leukocyte for phagocytosis
Opsonins
Principle mediators of vasodilation
Histamine and NO
Principle mediators of increased vascular permeability
Histamine and Bradykinin