Head blood vessels. Anatomical model of the blood vessels of the head in a dissected human skull. The head veins (black) drain deoxygenated blood out through the neck. The head arteries (red) bring oxygenated blood to the head through the neck. The branching blood vessels reach all parts of the head, allowing oxygen to be exchanged with body tissues for the waste gas carbon dioxide. The eyes and mouth are seen, but the brain (an organ that requires a major supply of blood) has been removed. The main vessels of the right-hand side of the neck (lower left) are the carotid artery (red) and the jugular vein (black).