io8 THORAX 



where it ends in the commencement of the right innominate 

 vein. This is the right lymphatic duct. Immediately before 

 its termination it may be joined by the right common 

 jugular and right subclavian lymphatic trunks, but, as a 

 rule, the two latter vessels' open separately into the sub- 

 clavian, the internal jugular, or the innominate veins (Parsons). 

 The right lymphatic duct conveys lymph from the upper part 

 of the right lobe of the liver, the right side of the thorax, 

 including the right pleura and lung and the right half of the 

 heart, and, if it is joined by the jugular and subclavian trunks, 

 the lymph from the right upper extremity and the right side 

 of the head and neck also. 



Lymphoglandulse Thoracales. During the dissection of the thorax 

 the dissector will have noted certain groups of lymph glands. These 

 are of considerable importance, for their enlargement in disease is not 

 infrequently the cause of serious thoracic trouble ; but whilst some, such 

 as the bronchial glands, are quite obvious, others are frequently so 

 small that they escape notice. The following are the chief groups: (i) 

 Two chains of minute glands which are placed in relation to the anterior 

 thoracic wall and follow the course of the internal mammary vessels. They 

 are termed sternal lymph glands, and are joined by lymphatic vessels from 

 the anterior thoracic wall, the mammary glands, the anterior part of the 

 diaphragm, and the upper part of the anterior wall of the abdomen. (2) Two 

 chains of glands on the posterior thoracic wall one on either side of the 

 vertebral column in relation to the vertebral extremities of the ribs. These are 

 very minute ; afferents to them accompany the intercostal vessels ; therefore 

 they are called the intercostal lymph glands, and they receive the lymphatics 

 of the posterior thoracic wall. (3) Anterior mediastinal lymph glands, 

 two or three in number, which receive lymphatics from the diaphragm 

 and upper surface of the liver. They occupy the lower open part of 

 the anterior mediastinum. (4) Posterior fnediastinal lymph glands, which 

 follow the course of the thoracic aorta, and are joined by lymphatics 

 from the diaphragm, pericardium, and oesophagus. (5) Superior media- 

 stinal lymph glands, an important group, eight to ten in number, and 

 placed in relation to the aortic arch and the bifurcation of the trachea. 

 The lymphatics of the heart, pericardium, and thymus enter these. (6) 

 Bronchial lymph glands, continuous above with the preceding, and 

 massed chiefly in the interval between the two bronchi. They are also 

 prolonged into the roots of the lungs. The lymphatic vessels of the lungs 

 pour their contents into them. In the adult, they are generally dark in 

 colour, and sometimes quite black. 



Dissection, Cut through the descending aorta immediately above the 

 diaphragm. Detach its upper end from the left vagus and the left recurrent 

 nerve which were previously fastened to it, then draw it forwards and 

 divide the intercostal and subcostal arteries, which arise from its posterior 

 surface, close to their origins and remove it. 



Arterise Intercostales. There are eleven pairs of inter- 

 costal arteries. The upper two pairs are derived indirectly 



