It’s a single layer of endothelium cells and some connective tissue. This layer sometimes contains one-way valves, especially in the veins of your arms and legs. These valves prevent blood from flowing backward. Veins are often categorized based on their location and any unique features or functions.
The pancreatic veins ( vv. pancreaticæ) consist of several small vessels which drain the body and tail of the pancreas, and open into the trunk of the lienal vein. The inferior mesenteric vein ( v. mesenterica inferior) returns blood from the rectum and the sigmoid, and descending parts of the colon.
The low pressure venous system needs the contraction of muscles to return the blood to the heart. There are four major types of veins. Examples include pulmonary and systemic veins as well as superficial and deep veins. Pulmonary veins carry oxygenated blood to the heart’s left atrium from the lungs,…This diagram with labels depicts and explains the details of Vein System Of The Human Body 744×1195.