Search results
Results from the WOW.Com Content Network
η(δ) = viscosity of blood in the wall plasma release-cell layering; r = radius of the blood vessel; δ = distance in the plasma release-cell layer; Blood resistance varies depending on blood viscosity and its plugged flow (or sheath flow since they are complementary across the vessel section) size as well, and on the size of the vessels.
In medium and large sized veins the flow of blood is maintained by one-way (unidirectional) venous valves to prevent backflow. [3] [1] In the lower limbs this is also aided by muscle pumps, also known as venous pumps that exert pressure on intramuscular veins when they contract and drive blood back to the heart. [4]
A valve system in place here prevents the absorbed lymph from leaking back into the interstital fluid. This valve system involves collagen fibers attached to lymphatic endothelial cells that respond to increased interstitial fluid pressure by separating the endothelial cells and allowing the flow of lymph into the capillary for circulation. [5]
Blood vessels transport blood cells, nutrients, and oxygen to most of the tissues of a body. They also take waste and carbon dioxide away from the tissues. [ 2 ] Some tissues such as cartilage , epithelium , and the lens and cornea of the eye are not supplied with blood vessels and are termed avascular .
Most vessels of the microcirculation are lined by flattened cells of the endothelium and many of them are surrounded by contractile cells called pericytes.The endothelium provides a smooth surface for the flow of blood and regulates the movement of water and dissolved materials in the interstitial plasma between the blood and the tissues.
The blood clot contains the secondary hemostasis plug with blood cells trapped in it. This is a necessary step for wound healing , but it has the ability to cause severe health problems if the thrombus becomes detached from the vessel wall and travels through the circulatory system; If it reaches the brain, heart or lungs it could lead to ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The endothelium (pl.: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. [1] The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall.