THOEACIC DUCT IN MAN 235 



Group VIII 



In, case 21 Tfig. 30) the thoracic duct begins in the abdominal 

 cavity from a plexus of lymphatic vessels and passes cephalad into 

 the thorax. In its course through the thorax, it lies to the right 

 of the aorta, placed between it and the vena azygos major. At 

 the level of the lower third of the 1st thoracic vertebra, the duct 

 divides into two branches which do not become reunited before 

 emptying into the venous system of the right side. The cephalic 

 branch ascends to the 6th cervical vertebra opposite the body of 

 which it begins to incline to the right and divides into two branches 

 which become united again after a course of 20 mm. to form a 

 single trunk which opens into the right internal jugular trunk 

 which opens into the right internal jugular vein a short distance 

 cephalad of its junction with the right subclavian vein. Another 

 branch is given off from this cephalic branch just after it bifur- 

 cates and which opens into the right internal jugular vein cephalad 

 to the opening of the branch just described. The more caudal 

 branch of the thoracic duct passes cephalo-laterad, then iatero- 

 caudad and ventrad to open into the posterior aspect of the right 

 internal jugular vein. 



The thoracic duct receives the lumbar and intestinal lymphatics 

 in its abdominal portion, collaterals in its abdominal portion, 

 collaterals draining the intercostal spaces in its thoracic portion, 

 and the right internal jugular lymphatic trunk in its cervical 

 portion. 



There are no vascular peculiarities associated with the duct 

 in this case and there is a left lymphatic duct comparable to the 

 usual right lymphatic duct. 



Watson (72), Todd ('39), Haller (75), Cruickshank ('90), 

 and Fleischmann ('15) describe cases similar to this, in which 

 the thoracic duct runs its entire course on the right side and 

 opens into the venous system at the base of the neck on the 

 right side. This type of thoracic duct belongs clearly to Type 

 8 of my classification. It occurred in 1 case out of 22 in my 

 series, or in 4.545 per cent. 



