Inferior thyroid veins Inferior thyroid veins The inferior thyroid veins appear two, frequently three or four, in number, and arise in the venous plexus on the thyroid gland, communicating with the middle and superior thyroid veins. While the superior and middle thyroid veins serve as direct tributaries to the internal jugular vein, the inferior thyroid veins drain directly to the brachiocephalic veins. They form a plexus in front of the trachea, behind the Sternothyreoidei. From this plexus, a left vein descends and joins the left brachiocephalic vein, and a right vein passes obliquely downward and to the right across the brachiocephalic artery to
Pulmonary vein drain into the pulmonary circulation in whole or in part, this is known as a total anomalous pulmonary venous connection (or drainage), or partial anomalous pulmonary connection, respectively. Pulmonary vein The pulmonary veins are the veins that transfer oxygenated blood from the lungs to the heart. The largest pulmonary veins are the four "main pulmonary veins", two from each lung that drain into the left atrium of the heart. The pulmonary veins are part of the pulmonary circulation. Two main pulmonary veins emerge from each lung hilum, receiving blood from three or four bronchial veins apiece and draining into the