112 SURGICAL ANATOMY OF 



serious. It can be tied easily in the first three intercostal 

 spaces, by making an oblique incision about two inches 

 long from without inwards, and at about three or four 

 lines from the border of the sternum, and the structures 

 divided in reaching it are integument, cellular tissue, 

 origin of pectoralis major, internal intercostal muscle. 

 Owing to its free anastomoses, of course both ends of the 

 wounded vessel require ligature. The close neighbor- 

 hood of the ribs to the lungs and pleura, liver and 

 diaphragm, render fractures by direct violence often very 

 serious from puncture of these structures by the frag- 

 ments. In indirect violence the rib is broken, as a rule, 

 near the angle, and there, save danger from punctures, 

 wounds of the intercostal arteries are rare; these vessels 

 are difficult to secure, from their position. 



Each intercostal artery is accompanied by a vein and 

 nerve, the nerve being superior to the artery in the upper 

 intercostal spaces, but below after the fourth or sixth 

 space. 



They are protected from pressure whilst the intercos- 

 tals are acting, by being inclosed in tendinous bands, 

 which are attached to the ribs. 



Mamma. The breast is situated in front of the pec- 

 toralis major, towards the lateral aspect of the region 

 of the chest, and corresponds to the interval between the 

 third and seventh ribs (the male nipple lies on the fourth 

 rib). It consists of gland and fibrous tissues arranged 

 in lobes; these are very numerous, the septa between 

 them being filled up by fat. Each lobe is again divisi- 

 ble into lobules, which are connected by areolar tissue, 

 bloodvessels, and ducts. The lobules open into the 

 lactiferous ducts, which uniting form larger ones, termi- 

 nating in an excretory duct, and are generally from fif- 



