Lingual veins Lingual veins The lingual veins begin on the dorsum, sides, and under surface of the tongue, and, passing backward along the course of the lingual artery, end in the internal jugular vein. The vena comitans of the hypoglossal nerve (ranine vein), a branch of considerable size, begins below the tip of the tongue, and may join the lingual; generally, however, it passes backward on the hyoglossus, and joins the common facial. The lingual veins are important clinically as they are capable of rapid absorption of drugs; for this reason, nitroglycerin is given under the tongue to patients suspected of having
Hepatic veins ultimately from numerous central veins of the liver lobules. None of the hepatic veins have valves. The hepatic veins are divided into an upper and a lower group. The upper three drain the central veins from the right, middle, and left regions of the liver and are larger than the lower group of veins. The lower group of from six to twenty smaller hepatic veins come from the right lobe and the caudate lobe, are in contact with the hepatic tissue, and are valveless. All the veins empty into the inferior vena cava at the back of the liver. Budd–Chiari