Study Set Content:
denotes an excess of fluid in the interstitial tissue or serous cavities; it can be either an exudate or a transudate.
Edema
a purulent exudate, is an inflammatory exudate rich in leukocytes (mostly neutrophils), the debris of dead cells, and, in many cases, microbes.
Pus
substances that initiate and regulate inflammatory reactions
MEDIATORS OF INFLAMMATION
induced by the action of several mediators, notably histamine, on vascular smooth muscle.
Vasodilation
earliest manifestations of acute inflammation.
Vasodilation
Vasodilation is quickly followed by
increased permeability of the microvasculature
These changes result in engorgement of small vessels with slowly moving red cells
Stasis
resulting in opening of interendothelial gaps is the most common mechanism of vascular leakage.
Contraction of endothelial cells
The journey of leukocytes from the vessel lumen to the tissue is a multistep process that is mediated and controlled by:
Adhesions molecules and cytokine called chemokines
This process can be divided into sequential phases:
- In the lumen: Margination, rolling and adhesion to endothelium
- Migration across endothelium and vessel wall
- Migration in the tissues
This process of leukocyte redistribution
Margination
The initial rolling interactions are mediated by _____
Selectins
The two major families of proteins involved in leukocyte adhesion and migration
Selectins & Integrins
The ligands for selectins are
sialylated oligosaccharides bound to mucin-like glycoproteins.
L-Selectin -
P-Selectin -
E-Selectin -
L-Selectin - leukocytes
E-Selectin - Endothelium
P-Selectin - Plasma
The expression of selectins and their ligands is regulated by what protein
Cytokines
Tissue macrophages, mast cells, and endothelial cells that encounter microbes and dead tissues respond by secreting
cytokines such as TNF, IL-1, and Chemokines
act on the endothelial cells of postcapillary venules adjacent to the infection and induce the coordinate expression of numerous adhesion molecules.
TNF & IL-1
stimulate the redistribution of P-selectin from its normal intracellular stores in endothelial cell granules to the cell surface
Histamine & thrombin
Other mediators such as histamine and thrombin, described later, stimulate the redistribution of P-selectin from its normal intracellular stores in endothelial cell granules or also called
Weibel-Palade bodies
