152 HANDBOOK OF ANATOMY 



right auricle. It receives the blood from the walls of the 

 heart. 



The Superior Vena Cava is formed at the lower border of 

 the first right costal cartilage by the junction of the two in- 

 nominate veins, descends to the level of the third right costal 

 cartilage, where it enters the right auricle. Anteriorly it is 

 overlapped by the right lung, and pleura and the ascending 

 aorta. 



Tributaries. Vena azygos major. 



Small pericardial veins. 



The Vena azygos major is the upward continuation of a vessel 

 known as the right ascending lumbar vein, which connects 

 together the lumbar veins of the right side. It passes through 

 the aortic opening in the diaphragm, up the posterior thoracic 

 wall, and arches over the root of the right lung to enter the 

 superior vena cava. It receives the right intercostal veins and 

 the vena azygos minor superior and inferior, which receive the 

 lumbar and intercostal veins of the left side. 



The Innominate Vein of each side is formed behind the 

 sternal end of the clavicle by the union of the internal jugular 

 with the subclavian vein. The two innominate veins unite to 

 form the superior vena cava behind the first right costal 

 cartilage; consequently the left one is longer than the 

 right. 



The tributaries are the veins corresponding to the arteries in 

 that region viz., internal mammary, inferior thyroid, vertebral,, 

 pericardial, and bronchial. 



The Internal Jugular vein commences as the direct continua- 

 tion of the lateral sinus of the brain, and passes through the 

 jugular foramen to reach the neck, uniting behind the sternal 

 nd of the clavicle with the subclavian vein to form the -innomi- 

 nate vein. It lies on the outer side of the common carotid 

 artery, and on the left side overlaps it in front at its 

 lower end. 



Tributaries. Sinus in the brain. 



Veins from the wall of the pharynx, the tongue,, 

 and the veins accompanying the thyroid 

 arteries. 



