344 A MANUAL OF ANATOMY. 



mogastric nerves, pleural sacs, and lungs. Aorta at left 

 and vena azygos major at right. Behind, longus colli muscle, 

 dorsal vertebrae, thoracic duct, third, fourth, and fifth right 

 intercostal arteries, left lower azygos vein, aorta, right 

 pneumogastric nerve. 



DISSECTION. 



Remove the oesophagus, tying a cord around its lower end as it passes 

 through the diaphragm. 



The Thoracic Duct. Diags. 20 to 23. 



This begins in the abdomen as the duct of the recepta- 

 culum chyli in front of the first and second lumbar vertebrae 

 and behind the abdominal aorta. 



The duct passes into the thorax through the aortic open- 

 ing at the right of the artery, and then along the front of 

 the spine, between the thoracic aorta on the left and the 

 vena azygos major on the right, until at the third dorsal 

 vertebra it turns to the left behind the aortic arch and 

 oesophagus. It passes upward at the left of the latter into the 

 neck, arches over the left subclavian artery and the apex of 

 the left lung to empty into the junction of the left jugular 

 and subclavian as they are forming the left innominate vein. 



At its opening into the vein there are two valves found. 

 Other valves similar to those found in the veins are dis- 

 tributed throughout its length. It is about fifteen or 

 eighteen inches long, and in diameter varies from one-fourth 

 to one-sixth of an inch. 



The thoracic duct receives the drainage from the lower 

 extremities, abdominal organs (excepting the upper surface 

 of the liver and abdominal walls), left lung, left side of the 

 heart, left upper extremity, and left side of the head and neck. 

 It empties all this collection into the beginning of the left 

 innominate vein. 



