136 THORAX 



a beaded or nodulated appearance on account of the 

 numerous valves which lie in its interior. The terminal 

 valve is usually situated a short distance from the point of 

 entrance of the duct into the left innominate vein. 



The Right Lymph Duct. From the level of the fifth 

 thoracic vertebra a small lymph vessel, the broncho-mediastinal 

 lymph trunk, may be traced upwards along the front of the 

 vertebral column to the root of the neck. At its com- 

 mencement in the superior mediastinum it not uncommonly 

 communicates with the thoracic duct. It either ends in the 

 commencement of the right innominate vein, or it joins 

 with the right jugular and right subclavian trunks, to form a 

 short stem, the right lymph duct; but, as a rule, the three 

 trunks open separately into the subclavian, the internal 

 jugular, or the innominate vein (Parsons). The right 

 broncho-mediastinal trunk 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 a right lymphatic duct is formed it receives the 

 lymph from the right upper extremity and the right side of 

 the head and neck as well as the lymph carried by the 

 broncho-mediastinal trunk. 



Lymphoglandulse Tkoracales. 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 broncho - pulmonary and tracheo - 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 along the course of 

 the internal mammary vessels. They are termed sternal lymph glands, 

 and are joined by lymph 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 each side of the vertebral column in 

 relation to the posterior parts of the intercostal spaces and the vertebral 

 extremities of the ribs. These are very minute ; they are called the inter- 

 costal lymph glands, and they receive the lymph vessels of the posterior 

 thoracic wall. (3) Lower anterior mediastinal lymph glands, two or three 

 in number, which receive lymph from the diaphragm and upper surface 

 of the liver. They occupy theJower open part of the anterior mediastinum. 

 (4) Upper anterior mediastinal lymph glands, an important group, eight 

 to ten in number, and placed in relation to the aortic arch and the great 

 vessels. They receive lymph from the heart, the pericardium, and the 

 thymus. (5) Posterior mediastinal lymph glands, which follow the course of 

 the thoracic aorta, and are joined by lymph vessels from the diaphragm- 

 pericardium and oesophagus. (6) Trachea-bronchial and intertracheo, 



