Veins

Veins function to return poorly oxygenated blood to the heart, and are essentially tubes that collapse when their lumen are not filled with blood. The thick, outer-most layer of a vein is made of collagen, wrapped in bands of smooth muscle while the interior is lined with epithelial cells called intima. Most veins have one-way flaps called venous valves that prevent blood from flowing back and pooling in the lower extremities due to the effects of gravity. The precise location of veins is much more variable from person to person than that of arteries.

Tissue Engineering of veins
Scientists Discover How To Grow Human Veins http://www.dailyhealthreport.org/scientists-discover-how-to-grow-human-veins/1496/

Veins of the neck
The venous return is accomplished through several smaller veins that merge to form the facial, superficial temporal, and maxillary veins. These veins then merge and drain into either the internal jugular vein or the external jugular vein, which drain into the subclavian vein and then into the brachiocephalic vein and then into the superior vena cava.

Zamboni's theory is that blockages in the veins leading from the head may cause iron deposits to develop in the brain. These deposits may cause Multiple Sclerosis.

http://singularityhub.com/2010/03/22/cure-for-multiple-sclerosis-verified-in-latest-research-trials-coming-soon/