Neurovascular bundle fluid and blood, they tend to have large surface area and short diffusion path. Normally, capillaries consist of a central lumen lined with an endothelium, a single layer of smooth epithelial cells. In contrast, deep neurovascular bundles, with arteries in them, have a more complicated composition. Arteries are the vessels that transfer the blood pumped by the heart to the entire body. Arteries have high intraluminal blood pressure, relative to capillaries and veins. To compensate arteries have a smooth muscle and a connective tissue structure outside the endothelium. This composition allows arteries to contract/relax, be flexible under pressure, and transfer
Lumbar veins Lumbar veins The lumbar veins are veins running along the inside of the posterior abdominal wall. They are the lumbar equivalent of the posterior intercostal veins. They are four in number and accompany the four lumbar arteries, with the vein lying superior to the artery (the same arrangement as in the intercostal neurovascular bundles). The first and second lumbar veins usually join the ascending lumbar vein rather than the inferior vena cava, which then joins the subcostal vein of the same side to form the azygous vein on the right or hemiazygous vein on the left. The third and fourth