Internal Mammary Artery 15 c 



pierce the pericardium. It receives most of the right intercostal 

 veins, and, from the left side, the smaller azygos (v. p. 185), 



When the inferior cava is blocked, as by an hepatic cancer, venous 

 blood from the lower part of the body finds a free collateral return to 

 the heart through the vena azygos major, which may thus become as 

 large as the thumb. 



Thymus gland in a child of six m 



(SAPPEY.) 



i and 2, Right and left lobes ; 4, lung ; 6, thyroid ; 7 and 8, inf. thyroid veins ; o, com. car. 

 art. ; 10, int. jug. vein ; u, vagus. 



The internal mammary artery, from the first part of the sub- 

 clavian (p. 228), enters the thorax behind the first costal cartilage, and, 

 descending behind the intercostal spaces, about -inch from the border 

 of the sternum, divides behind the seventh cartilage into the musculo- 

 phrenic and superior epigastric. At first the artery lies behind the 

 subclavian vein and in front of the pleura, being crossed obliquely by 

 the phrenic nerve ; but, lower down, the triangularis sterni separates 

 it from the pleura. 



