658 THE LYMPHATICS 



II. THE VISCERAL LYMPHATIC VESSELS AND GLANDS OF . 



THE THORAX 



1. The visceral lymphatics of the thorax include those from the heart and 

 pericardium, the lungs and visceral pleura, the (psophagus and the thymus gland, 

 with the glands into which these lymjihatics respectively open — namely, the ante- 

 rior mediastinal, the superior mediastinal, the posterior mediastinal, and the 

 bronchial. 



The lymphatics of the pericardium end in front in the anterior mediastinal 

 and superior mediastinal glands, and behind in the posterior mediastinal glands. 



The lymphatics of the heart l)egin at the apex, and follow the coronary ves- 

 sels to the base, where they leave the pericardium, and imite to form a right and 

 a left trunk. The former passes over the arch of the aorta, then through one of the 

 superior mediastinal or cardiac glands, and thence backwards to the trachea, on 

 which it runs to join the right lymphatic duct at the root of the neck. The left 

 trunk courses along the pulmonary artery, and, at the bifurcation of that vessel, 

 passes through one of the posterior mediastinal glands behind the arch of the 

 aorta, and thence runs up the left side of the trachea to end in the thoracic duct. 



The lymphatics of the visceral pleura and lung form a st^perficial set 

 beneath the pleura, and a deep set which accompanies the pulmonary vessels and 

 bronchial tubes. At the root of the lung the superficial join the deep, which then 

 enter the bronchial glands. 



The lymphatics of the thoracic portion of the oesophagus l^egin as a 

 plexus ])etween the mucous membrane and the muscular coat, perforate the latter, 

 and terminate in the i)()sterior mediastinal glands. 



The lymphatics of the thymus terminate in the superior mediastinal glands. 



2. The visceral lymphatic glands are the anterior mediastinal, the superior 

 mediastinal, the {Hjsterior mediastinal, and the l:)ronchial. 



The anterior mediastinal or sternal glands lie in front of the pericardium 

 behind the sternum in the loose tissue of the anterior mediastinum. They receive 

 the lymphatics from the antero-median portion of the diaphragm, the front of the 

 pericardium and heart, some of the efferent vessels from the lower internal mammary 

 lymphatic glands, and the lymphatics from the convex surface of the right lol)e of 

 the liver. Their efferent vessels pass u])wards to the superior mediastinal glands. 



The superior mediastinal or cardiac glands lie in front of the upper part of 

 the pericardium, the arch of the aorta, and left innominate vein. They receive 

 the lymphatics from the anterior mediastinal glands, from the upper and front ]iart 

 of the pericardium and right side of the heart, and from the thymus gland. 

 Their efferent vessels run up the sides of the trachea to join the thoracic duct 

 and right lymphatic duct respectively. 



The posterior mediastinal glands are situated in the posterior mediastinum 

 along tlie course of the aorta and crsophagus. They receive lymphatics from the 

 back of the pericardium and left side of the heart, from the oesophagus, from the 

 ])osterior part of the diaphragm, and a few from the right border of the livtM". 

 Their efferent vessels pass chieffy into the thoracic duct; a few into the broneliial 

 glands. 



The bronchial glands are placed between the divisions of the ])ronchi at the 

 root of the lung (pulmonary glands), and al)out the Infurcation of the trachea 

 (tracheal glands). The larger glands, situated at the bifurcation of the trachea, 

 are twenty or thirty in number. They receive the ]ym})hatics from the lung and 

 visceral ])leura; also some of the lym])hatics from the trachea and from the back 

 of the lieart and ])ericar(lium, and a few of the efferent vessels of the posterior 

 mediastinal glands. Their efferent vessels, with the efferent vessels of the sujjerior 

 mediastinal or cardiac glands, pass up the sides of the trachea, and on the riglit 

 side either terminate directly in the right lymphatic duct, or join with tlie efferent 

 vessels of the intercostal glands to form a common trunk, the broncho-mediasti- 

 nal trunk, and thus open into the right lymphatic duct. On the left side they 

 open directly into the thoracic duct, or first form, as on the right side, a broncho- 

 mediastinal trunk. 



