postcapillary venules

post·cap·il·lar·y ven·ules

the microvasculature immediately following the capillaries, ranging in size from 10-50 mcm, and characterized by investment of pericytes; they are the site of extravasation of blood cells, are particularly sensitive to histamine, and are believed to be important in blood-interstitial fluid exchanges.
Synonym(s): pericytic venules

post·cap·il·lar·y ve·nules

(pōst-kap'i-lar-ē ven'yūls)
The microvasculature immediately following the capillaries, ranging in size from 10-50 mcm, and characterized by investment of pericytes; they are the site of extravasation of blood cells, are particularly sensitive to histamine, and are believed to be important in blood-interstitial fluid exchanges.
Synonym(s): pericytic venules.
References in periodicals archive ?
vasodilator of postcapillary venules which cause increased vascular permeability in postcapillary venules, leading to protein extravasation (tissue edema)
Together, the arterioles, associated capillary network, and postcapillary venules form a functional unit called the microcirculatory or microvascular bed of that tissue.
Increased permeability results mainly from actions of histamine on postcapillary venules, where histamine causes the endothelial cells to contract and separate at their boundaries (Goodman-Gilman 1990).
This swelling condition is a result of interstitial edema from vasoactive mediators increasing the permeability of postcapillary venules of the subcutaneous and submucosal tissues.
In Type III reaction, complexes formed by the drug or its metabolite and specific IgG and IgM antibodies developed against these are deposited in postcapillary venules.
Another notable feature is the use of a simple off-the-shelf tube that is the size (300 [micro]m) and shape of postcapillary venules where endothelial cells are stimulated by inflammatory stimuli.
Amazingly, he demonstrated that nothing happened in the capillaries but that there was separation of the endothelial cells in postcapillary venules, which was the pathogenesis of the vascular leak; this totally unexpected observation is widely regarded as one of the major discoveries in experimental vascular pathology.
Hemangiopericytoma is an uncommon hypervascular mesenchymal neoplasm originating from modified contractile smooth-muscle cells that surround capillaries and postcapillary venules, called pericytes of Zimmerman.
The capillary hydrostatic pressure is regulated by the smooth muscle tone in the precapillary arterioles and the postcapillary venules.
Furthermore, it is not always possible to distinguish lymphatic vessels from postcapillary venules because both are small, thin-walled structures.