154 SURGICAL APPLIED ANATOMY. [Chap. x. 



In cancer, the gland and the muscle may become 

 intimately adherent. The nipple is situated over the 

 fourth interspace, about three-quarters of an inch 

 from the junction of the ribs with their cartilages, 

 and some four inches from the middle line. It 

 contains muscular fibres, by means of which it can be 

 rendered prominent on stimulation. The skin about 

 the nipple is very thin and sensitive, and is often the 

 seat of painful fissures and excoriations. When any 

 contracting growth, such as scirrhus, drags upon the 

 ducts of the gland, the nipple becomes retracted. 



Abscesses of the breast should be opened by in- 

 cisions radiating from the nipple, so as to avoid un- 

 necessary damage to the mammary ducts. 



The breast is supplied by the anterior cutaneous 

 branches of the second, third, fourth, and fifth inter- 

 costal nerves, and by the lateral branches of the last 

 three of those nerves. The connections of these 

 trunks serve to explain the diffusion, of the pain 

 that is sometimes observed in painful affections of 

 the gland. Thus in abscess of the breast pain is 

 often felt round the side of the thorax to the back, 

 following the trunks of the above-named intercostal 

 nerves ; or it is distributed over the scapula by the 

 cutaneous branches of the posterior divisions of such 

 dorsal nerves as correspond to the intercostal trunks 

 that supply the breast ; or it runs down the arm 

 along the intercosto-humeral nerve (a branch of the 

 second intercostal), or shoots up the neck, probably, 

 along the supra-clavicular branch from the cervical 

 plexus, which communicates with the same intercostal 

 trunk. 



The gland is supplied by the following arteries, 

 which are divided in excision of the organ : the 

 second, third, fourth, and fifth intercostal branches 

 of the internal mammary artery, some few branches 

 from the corresponding intercostal vessels, the long 



