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
Smallest cardiac veins Smallest cardiac veins The smallest cardiac veins (or Thebesian veins) are minute valveless veins in the walls of all four heart chambers. The veins are sometimes accurately referred to as vessels, but they are frequently confused with a distinct set of artery connections eponymously referred to as the "vessels of Wearn". In his 1928 publication, Wearn himself referred to the arterio-cameral connections (vessels of Wearn) as thebesian. However, Wearn's 1933 and 1941 publications emphatically described the thebesian veins as distinct from arterio-cameral vessels. The thebesian veins are reportedly most abundant in the right atrium and least in the left ventricle.