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
Vorticose veins vortex veins drain into the superior orbital veins and thence to the cavernous sinus. Some vortex veins drain into the inferior orbital vein which drains into the pterygoid plexus. There is usually collateral circulation between the superior and inferior orbital veins. Vorticose veins The vorticose veins, referred to clinically as the vortex veins, drain the ocular choroid. The number of vortex veins is known to vary from 4 to 8 with about 65% of the normal population having 4 or 5. In most cases, there is at least one vortex vein in each quadrant. Typically, the entrances to the vortex