104 THE POCKET ANATOMY 



Internal mammary : two with each artery, uniting in a 

 single trunk, emptying into innominate veins. 



Inferior thyroid (sometimes 3 or 4) : from thyroid venous 

 plexus, emptying into right and left innominate veins. 



Superior intercostal : receives veins from 2nd and 3rd 

 intercostal spaces. The right one passes down and enters the 

 azygos major, the left passes forward across arch of aorta 

 to left innominate vein, and receives the left bronchial 

 vein. 



Vena cava superior : 3 inches long, formed by the junction 

 of the right and left innominate veins behind the junction of 

 the ist right costal cartilage with the sternum ; passes down 

 to the right auricle opposite upper border of 3rd right costal 

 cartilage. The vena cava enters the pericardium about 

 i inches from its termination, and this part is covered with 

 serous membrane except posteriorly. No valves. Receives 

 pericardial and mediastinal veins, and just as it enters the 

 pericardium the azygos major vein. 



Relations : 



Left Side. In Front. Right Side. 



Innominate artery, in Pleura. Pleura. 



upper part. Thymus gland. Right phrenic nerve. 



Ascending part of aortic Costal cartilages and 

 arch, in lower part. intercostal spaces. 



Pericardium. 



Behind. 

 Pleura. 



Right bronchus. 

 Right pulmonary artery. 

 Upper right pulmonary vein. 

 Pericardium. 



Azygos major: commencing opposite ist or 2nd lumbar 

 vertebra by a branch from right lumbar veins, passes up 

 through aortic opening in diaphragm to right of aorta, and 

 along right side of column in front of right intercostal 

 arteries to 3rd dorsal vertebra, where, arching over root of 

 right lung, it empties into superior vena cava. Receives the 

 ten lower right intercostal veins, venae azygoi minores 

 (superior and inferior), several cesophageal, mediastinal, and 

 right bronchial veins. Imperfect valves, though its branches 

 have complete ones. 



Azygos minor inferior : commencing in lumbar region of left 

 side from lumbar veins, or branches of renal, passes through 

 left crus of diaphragm to 8th dorsal vertebra, there crossing 

 behind aorta and thoracic duct to terminate in azygos major. 



