Search results
Results From The WOW.Com Content Network
Post-capillary venules are the smallest of the veins with a diameter of between 10 and 30 micrometres (μm). When the post-capillary venules increase in diameter to 50μm they can incorporate smooth muscle and are known as muscular venules. [1] Veins contain approximately 70% of total blood volume, while about 25% is contained in the venules. [2]
The venous system apart from the post-capillary venules is a high volume, low pressure system. Vascular smooth muscle cells control the size of the vein lumens, and thereby help to regulate blood pressure. [31] The post-capillary venules are exchange vessels whose ultra-thin walls allow the ready diffusion of molecules from the capillaries. [10]
In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. [1] [2] It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and Latin vascula meaning vessels).
As a consequence, microcirculation blood flow remains constant despite changes in systemic blood pressure. This mechanism is present in all tissues and organs of the human body. In addition, the nervous system participates in the regulation of microcirculation. The sympathetic nervous system activates the smaller arterioles, including terminals.
In general, arteries and arterioles transport oxygenated blood from the lungs to the body and its organs, and veins and venules transport deoxygenated blood from the body to the lungs. Blood vessels also circulate blood throughout the circulatory system. Oxygen (bound to hemoglobin in red blood cells) is the most critical nutrient carried by ...
MECA-79+ venules with plump endothelium have also been detected in other sites of chronic inflammation, including many cutaneous inflammatory lesions. The presence of MECA-79+ HEV-like vessels in many different human chronic inflammatory diseases indicates that L-selectin is likely to play a major role in lymphocyte emigration at chronic ...
The capillaries connect to venules, and the blood then travels back through the network of veins to the venae cavae into the right heart. The micro-circulation — the arterioles, capillaries, and venules —constitutes most of the area of the vascular system and is the site of the transfer of O 2, glucose, and enzyme substrates into the
Circulatory system: ... The capillaries then join and widen to become venules, ... His 1922 estimate that total length of capillaries in a human body is as long as ...