THORACIC DUCT IN MAN 225 



Group VI 



In 14 instances in my series (figs. 16-29) the thoracic duct 

 begins in the abdominal cavity as a single trunk which passes 

 cephalad into the thorax and at the level of the 5th to the 

 3rd thoracic vertebra begins to incline to the left and finally 

 passes to the left of the median line of the bodies of the thoracic 

 vertebrae. The duct continues cephalad and at the level of the 

 2nd thoracic to the 6th cervical vertebra changes its course 

 passing cephalad, ventrad, and to the left, and then caudad and 

 slightly ventrad to open into the venous system at the base of 

 the neck. 



In 8 instances (figs. 16, 17, 20, 21, 23, 26, 27, 29), the 

 thoracic duct begins to incline to the left opposite the body of 

 the 5th thoracic vertebra; opposite the body of the 6th thoracic 

 vertebra in 1 instance (fig. 28) ; opposite the body of the 4th 

 thoracic vertebra in 4 instances (figs. 18, 19, 24, 25) ; and 

 opposite the body of the 3r.d thoracic vertebra in 1 instance 

 (fig. 22). The terminal portion of the thoracic duct changes its 

 course opposite the 2nd thoracic vertebra in 1 instance (fig. 20) ; 

 opposite the 1st thoracic vertebra in 6 instances (figs. 16, 17, 

 19, 21, 24, 26) ; opposite the 7th cervical vertebra in 6 instances 

 (figs. 18, 23, 25, 27, 28, 29) ; and opposite the 6th cervical verte- 

 bra in 1 instance (fig. 22). 



The mode of termination is somewhat variable. In 5 in- 

 stances (figs. 16, 20, 22, 27, 28) the thoracic duct terminates 

 by a single opening into the left subclavian vein; into the left 

 subclavian vein by 2 branches in 1 instance (fig. 17); into 

 the left angulus venosus by a single branch in 5 instances 

 (figs. 18, 19, 21, 24, 25) ; into the left angulus venosus by 2 branches 

 in 1 instance (fig. 29;) into the left internal jugular by a single 

 branch in 1 instance (fig. 26) ; and into the posterior wall of the 

 left innominate vein by a single branch in 1 instance (fig. 23). 



The thoracic ducts begin in the abdominal cavity by the 

 confluence of the lumbar lymphatics and sometimes the intestinal 

 trunk or by a lymphatic plexus in which the lumbar trunks are 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 17, NO. 2 



