966 



HUMAN ANATOMY. 



axillary fascia, or backward by reason of the attachment of the serratus magnus to the 

 scapula, or outward or inward because of the upper limb and the wall of the thorax. 

 It should be opened half way between the anterior and posterior folds near the 

 inner or thoracic wall. 



Intercostal node 



internal mammary 

 nodes 



THE LYMPHATICS OF THE THORAX. 



The Lymph-Ncdes. 



Certain of the nodes which have been described as belonging to the axillary 

 plexus, namely, .nose forming the anterior and inferior pectoral subgroups, might 

 well be considered as belonging to the thoracic set, since their afferents drain the 

 anterior and lateral walls of the thorax. On account of their situation, however, as 

 well as their intimate connection by elTerents with the intermediate and subclavicular 

 axillary nodes, they are more conveniently classed w^ith the axillary set. 



The remaining thoracic nodes may be divided into two sets according as they 

 occur in connection with the thoracic walls, parietal nodes, or with the viscera, 

 visceral nodes. Of the parietal nodes there ai e two principal groups. 



The sternal or internal mammary nodes (lymphoglandulae sternaies) form 

 two chains which extend upwards upon the inner surface of the anterior thoracic 

 wall, along the course of the internal mammary blood-vessels (Fig. 812). They vary 



in number from four to ten, 

 • • and are situated at the ante- 



rior or sternal ends of three 

 or more of the upper inter- 

 costal spaces, resting upon 

 the internal intercostal mus- 

 cles and being covered, so far 

 as the lower members of the 

 group are concerned, by slips 

 of the triangularis sterni. 

 Their affere7its come from 

 the anterior diaphragmatic 

 nodes, from the upper por- 

 tions of the rectus abdominis, 

 from the anterior portions of 

 the intercostal muscles, from 

 the integument over the ster- 

 num and costal cartilages, 

 and, to a certain extent, from 

 the mammary glands. Since 

 the nodes are arranged in 

 the form of a chain, the effer- 

 enis from the lower members 

 of the series are afferents for 

 the higher ones ; the terminal 

 ef?erents usually unite to form 

 a single stem which joins the efferents of the anterior mediastinal and bronchial nodes 

 to form the broncho-mediastinal trunk (page 968). 



The intercostal nodes flympho},Man(lulae intercostales) are situated along the 

 courses of the intercostal arteries, the principal and most constant members of the 

 series being situated towards the posterior extremities of the intercostal spaces. 

 Some nodes which occur in the lateral portions of the spaces are inconstant and 

 always small ; they are usually situated, when present, at the point where the 

 intercostal arteries give off their lateral perforating branches. 



The afferents of the intercostal nodes drain the posterior portions of the inter- 

 costal spaces. The efferents of the lower members of the series unite to form a stem 

 which passes downward and terminates in the receptaculum chyli, while those from 



Lower 



intermammary 

 node 



Lymph-nodes of anterior thoracic wall, viewed from beliind. 

 (Bused upon figure of Poirier and Ciineo.*) 



* Poirier et Charpy : Traits d'anatoniie humaine. Tome ii., 1902. 



