I032 A MANUAL OF ANATOMY 



Of the left side In the lower part of the thorax the thoracic duct is 



nL.'^if/'' ""^^'^r l^^" i" '^^ "PP^^ P^^t- Its course is somewhat 



esDecall^?; fhp ''^'" ^^'^^^^'^ ^' P^'^^^^*^ ^ beaded appearance 

 especially in the upper part, due to the number of valves with which 

 It is provided. Sometimes the duct divides into two branches 

 m the lower part of the thorax, which reunite at a higher kvel 

 The duct IS freely provided with valves, especially in its upper part* 

 and at its termination there is an important vllve, con^sfsting of 

 two segments, which are so directed as to prevent effectually the 

 reflux of chyle, or the flow of blood, into the duct ^ 



«;onrrP. "JxtTi, '1''^ '^""T^l lymphatic vessels from the following 

 sources . (i) the lower limbs ; (2) the abdomen and its viscera 

 except sonae of the lymphatics from part of the upper surface of 



th^ tT^: ?^ 'AV'^i^ ^"^^ °^ '^' ^^°^^^^^ ^^" ' f4) the^eft kng and 

 the left half of the heart ; (5) the left upper limb ; and (6) th! left 



b.tf 1/1?%^""^ and neck. Most of the lymphatics of the right 

 aiiall of the thorax and those of the right lung and right half of the 

 hearr uiP- ° ^J "?h* lymphatic duct, for the description of which 

 see the sectionr'ii^^^^^ng ^jjh the neck. 



Thoracic Lymphatic'"^<^i-^^^s-~These are arranged in several 

 groups, as follows : anterior intb^'^^ostal or sternal, posterior inter- 

 costal, superior mediastinal, anterior ^'i^ediastinal, posterior medias- 

 tinal, bronchial, and caval. 



The anterior intercostal or sternal glands will' be found described 

 on p. 933. They receive their afferent vessels fron'il (i) the anterior 

 parts of the upper six intercostal spaces ; {2) the iui'ier portion of 

 the mammary gland ; (3) the lymphatics accompanying uhe superior 

 epigastric artery from the upper part of the anterior afrdominal 

 wall ; and (4) the l^nrntphatics accompanying the musculo- phrenic 

 artery from the anterior parts of the seventh, eighth, and ninth 

 intercostal spaces, and from a portion of the diaphragm. The 

 efferent vessels of the right glands terminate in the right lymphatic 

 duct, and those of the left glands in the thoracic duct. 



The posterior intercostal glands are situated on either side of the 

 vertebral column, where they lie in the intercostal spaces, thers 

 being from one to three in each space. They receive their afferen*^ 

 vessels from (i) the posterior parts of the intercostal spaces ; 

 (2) the parietal pleura ; (3) the spinal canal ; and (4) the deep 

 muscles of the back. The efferent vessels of the left intercostal 

 glands open into the thoracic duct. On the right side the efferent 

 vessels from the lower glands pass to the thoracic duct, but those 

 from the upper glands open into the right lymphatic duct. 



The superior mediastinal glands lie in the superior mediastinum 

 in relation to the arch of the aorta and the innominate veins, and 

 they are continuous with the posterior mediastinal and bronchial 

 glands. They receive their afferent vessels from the pericardium, 

 the heart, and the thymus body in early life, and their efferent 

 vessels pass to the thoracic duct and right lymphatic duct. 



The anterior mediastinal glands lie in the lower part of the anterior 



