Blood vessel between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart. The word "vascular", meaning relating to the blood vessels, is derived from the Latin "vas", meaning vessel. A few structures (such as cartilage and the lens of the eye) do not contain blood vessels and are labeled. The arteries and veins have three layers. The middle layer is thicker in the arteries than it is in the veins: Capillaries consist of little more than a layer of endothelium and occasional connective tissue. When blood vessels connect to form a region of
Anterior spinal veins infiltrate back into the ventral median spinal fissure previously mentioned by up to a few centimeters. They are also not only smaller in size but more numerous than the equivalent anterior spinal artery which they lie dorsal to. There are three anterior spinal veins in total. These, along with three posterior spinal veins, are allowed to communicate with one another as they run interconnected throughout the entire length of the spinal cord. This is seen through both sets of veins combining to form a network of anastomoses around the conus medullaris. Together, these two sets of veins also collect blood