2i 4 APPLIED ANATOMY. 



Ulceration may cause fatal hemorrhage by involving the carotid arteries, more 

 likely the left, the inferior thyroids, the innominate, and even the aorta itself lower 

 down. Low down in the chest the pericardium is in front of the oesophagus, and 

 has been perforated. On the left side above and the right side below, the pleurae 

 have been perforated and the lungs involved. Abscesses may occur from the ulcer- 

 ative process and they are particularly dangerous, as the distance between the upper 

 portion of the sternum and anterior portion of the bodies of the vertebrae is so small 

 that compression of the air-passages and suffocation is readily produced. 



THE THORACIC DUCT. 



The thoracic duct carries not only lymph but also chyle which is emptied into the 

 venous system and goes to nourish the body. Therefore a wound of the duct with 

 the escape of its fluid may result fatally from inanition. The lymph coming from all 

 parts of the body is collected into two ducts, the right lymphatic duct and the thoracic 

 duct. Of these two the right lymphatic duct is the smaller. It collects the lymph 

 coming from the right side of the head and neck, right upper extremity, right side of 

 the thorax and the upper convex surface of the liver. The several lymphatic branches 

 unite to form a duct, one to two centimetres long, which empties into the venous 

 system at the junction of the right internal jugular and subclavian veins. At its point 

 of entrance it is guarded by a pair of valves. As this duct contains no chyle, and 

 lymph of only a portion of the body, wounds of it have not proved serious. 



The thoracic d^lct is much larger and more important. It begins on the 

 bodies of the first and second lumbar vertebrae to the right of the aorta in the 

 cisterna (receptaculum) chyli. 



The cisterna or receptaculum is 5 to 7.5 cm. long and 7 mm. wide. It receives 

 not only the lymph from the parts below but also the chyle from the intestines. It 

 passes through the aortic opening in the diaphragm with the aorta to the left and the 

 vena azygos major to the right. In the posterior mediastinum it lies on the bodies 

 of the seven lower thoracic vertebrae, with the pericardium, the oesophagus, and the 

 arch of the aorta in front. The thoracic aorta is to its left and the vena azygos major 

 and right pleura to its right. Above the fifth thoracic vertebra it ascends between the 

 oesophagus and left pleura, behind the first portion of the left subclavian artery. 

 On reaching the level of the seventh cervical vertebra it curves downward over the 

 left pleura, subclavian artery, scalenus anticus muscle, and vertebral vein to empty 

 at the junction of the internal jugular and left subclavian veins. It passes behind 

 left internal jugular vein and common carotid artery. At its termination it lies 

 just external to the left sternoclavicular joint and just below the level of the upper 

 border of the clavicle. A punctured wound at this point would injure the duct. 



Accompanying the veins of the neck are numerous lymph-nodes which not 

 infrequently become enlarged and require removal. It is in operating on these nodes 

 that wounds of the thoracic duct have been most often produced. When divided, its 

 lumen has appeared to be of the size of a "knitting needle." In some instances the 

 thin walls of the duct have been ligated. In other cases of injury either the oozing 

 point has been clamped with a haemostatic forceps which has been left in position for 

 a day, or else the wound has been packed with gauze. Recovery usually ensues. 



