486 



DISSECTION OF THE THORAX. 



It may be 

 divided ; 



is furnished 

 with valves ; 



receives 

 most lym- 

 phatics. 



Right duct 



receives 

 lymphatics 

 of one- 

 fourth of 

 body. 



Thoracic 

 cord of 

 sympathetic 



has twelve 

 ganglia. 



Opposite the fourth dorsal vertebra it passes beneath the aortic 

 arch, and is then applied to the left side of the oesophagus, on 

 which it is conducted to the neck under the left subclavian 

 artery. At the lower part of the neck it 

 arches outwards, external to the common 

 carotid artery and above or over the 

 subclavian artery, to open into the left 

 subclavian vein at its junction with the 

 internal jugular. 



In this course the tube is oftentimes 

 divided in two, which unite again ; or its 

 divisions may even form a plexus. Near 

 its termination it is frequently branched. 

 It is provided with valves at intervals, 

 like a vein : and these are in greatest 

 number at the upper part. 



Branches. In the thorax the duct re- 

 ceives the lymphatics of the left half of the 

 cavity, viz., from the sternal and inter- 

 costal glands ; also the lymphatics of the 

 left lung, the left side of the heart, and 

 the trachea and oesophagus. 



The RIGHT LYMPHATIC DUCT receives 

 large branches from the viscera of the 

 thorax, and is a short trunk in the neck, 

 about half an inch in length, which 

 opens into the angle of union of the sub- 

 clavian and jugular veins of the same side : 

 its opening is guarded by valves. 



Branches. Into this trunk the lym- 

 phatics of the right upper limb and right 

 side of the head and neck pour their 

 contents. In addition, the lymphatics of 

 the right side of the chest, right lung and 

 right half of the heart, and some from the 

 right lobe of the liver, after passing through 

 their respective glands, unite into a few 

 large trunks, which ascend beneath the in- 

 nominate vein to reach the duct in the neck. 



CORD OF THE SYMPATHETIC NERVE 



(fig. 174, p. 481). The thoracic part of 

 the gangliated cord of the sympathetic 

 nerve is covered by the pleura, and is 

 placed over the heads of the ribs and the 

 intercostal vessels. The ganglia on it are 

 usually twelve, one being opposite each 



dorsal nerve, but this number is frequently reduced by the fusion 

 of two adjoining ones. The first ganglion is the largest ; and the 

 last two are rather anterior to the line of the others, being situate 

 on the side of the bodies of the corresponding vertebrae. 



FIG. 175. THE THORACIC 



D0CT, AND THE AzYGOS 



VEINS. 



1. Thoracic duct. 



2. Ending of the duct 

 in the left subclavian vein. 



3. Large azygos vein. 



4. Left lower azygos 

 vein. 



5. Left upper azygos 

 vein. 



6. Vena cava superior. 



7. Left internal jugular 

 vein, cut through. 



