1110 



SURGICAL AND TOPOGRAPHICAL AX ATOMY 



remains of the thymus gland, the inferior thyroid veins, the trachea and tracheal 

 fascia, the oesopliagus and longus colh muscles, l^etween the trachea and 

 (Bsophagus are the recurrent laryngeal nerves. (2) On each side. The apex of 

 the lung, covered by pleura, rises about an inch and a half above the first rib. 

 Between it and the trachea and oesophagus lie the following: the internal mannnary 

 artery, the phrenic nerve; on the right side, the innominate vein and artery, with 

 the vagus between the two, the cardiac nerves, and the right lymphatic duct. On 

 the left side are the common carotid and subclavian arteries, Avith the left vagus 

 between them, the cardiac nerves, and the thoracic duct. Farthest l)ack and on 

 each side are the trunk of the sympathetic, the superior intercostal artery, and the 

 tirst tlioracic nerve. 



Structures found in an intercostal space. — (1) Skin; (2) superficial fascia, 

 with cutaneous vessels and nerves; (3) deep fascia; (4) external intercostal; (5) 

 cellular interval between intercostals, containing trunks of intercostal vessels and 

 nerves; (6) internal intercostals; (7) thin layer of fascia; (8) subpleural 

 connective tissue; (9) pleura (fig. 682). 



The mamma. — This lies partly over the sheath of the pectoralis major and 

 partly over the serratus magnus. It is usually described as reaching from the third 

 to the fifth or sixth rib, and from the sternum to the anterior border of the axilla. 

 It is most important to remember that the breast is often a much more extensive 

 structure than would be included in the above very limited description. Thus ( 1 ) the 

 breast is not encapsuled at its periphery, its tissue branching and breaking up here 



Fjg. 682. 



-Section of the Sixth Left Intercostal Space, at the Junction of 

 THE Anterior and PosT^:RIOR Tfiirds. (Tillanx.) 



Intercostal vein 



Intercostal artery 



INTERCOSTAL NERVE — 



Serratus magnus — 



Its aponeurosis — 



Aponeurosis covering external — 



intercostal muscle 



External intercostal muscle 



_ Aponeurosis covering the internal 

 intercostal muscle 

 Internal intercostal muscle 



to l)ecome continuous with the superficial fascia (Stiles). (2) The ligamenta 

 suspensoria contain breast tissue. (3) There is a lymphatic plexus, and, often, 

 minute lobules of breast tissue, in the pectoral fascia (Heidenhain). In the male 

 the nipple is placed in the fourth space, nearly an inch outside the cartilages of 

 the fourth and fifth ribs. On the nipple itself open the fifteen or twenty ducts 

 which dilate beneath it, and then diverge and break up for the supply of the 

 lobules. The skin over the aieola is very adherent, pigmented, and fatless. Here 

 also are groups of little swellings corresponding to some tAventy large sebaceous 

 follicles. The skin over the breast is freely movable, and united to the fascia 

 which encases the organ, and thus to the interlobular connective tissue, by bands 

 of the same structure — the ligamenta suspensoria. Under the l)reast, and giving it 

 its mobilit}^ is a cellulo-fatty layer, the seat of sulnnammary abscess. The nerves 

 which supply the breast are the anterior cutaneous branches of the second, third, 

 f(jurth, and fifth intercostal nerves, and the lateral l>ranches of the last three. The 

 connection of these trunks serves to' explain the diffusion of the pain often observed 

 in painful affections of the breast. Thus pain may be referred to the side of the 

 chest and l)ack (along the above intercostal trunks), over the scapula, along the 

 inner side of the arm (along the intercosto-humeral nerve, a branch of the second 

 intercostal), or up into the neck, probably along the supra-clavicular l)ranch from 

 the cervical plexus, whicli communicates witli the second intercostal (Treves). 

 The gland is su])])lied ])y tlie following arteries : the aortic intercostals of the 

 second, third, fourth, and fifth spaces, similar intercostal branches from the 



