HITCHCOCK'S ANATOMY 



170 



.Fig. 184. 



and terminate in the Thoracic 

 Duct. These at their com- 

 mencement are about the 

 same in anatomy with the 

 radicles or small veins, and 

 at this point act the part of 

 absorbents. Soon after they 

 have left the Intestines, sev- 

 eral of them unite into one 

 and pass through small bodies 

 of about the size of peas, 

 called the Mesenteric Glands. 

 As they emerge from these 

 glands, they are fewer in 

 ftumber but larger in size, 

 until they all unite into one 

 tube called the Thoracic Duct, 

 a little larger than a goose 

 quill, at about the point of 

 the last Dorsal Vertebra. 

 This vessel passes immedi- 

 ately upwards, lying closely 

 upon the Spinal Column, 

 sometimes separating into two 

 smaller tubes for a few inches, 



A View of the Course and Termination of the Thoracic Duct. 1, Arch of the Aorta. 

 2, Thoracic Aorta. 3, Abdominal Aorta. 4, Arteria Innominata. 5, Left Carotid. 6, 

 Left Sub-Clavian. 7, Superior Cava. 8, The two Venae Innominatse. 9, The Internal 

 Jugular and Sub-Clavian Vein at each side. 10, The Vena Azygos. 11, The Termina- 

 tion of the Vena Hemi-Azygos in the Vena Azygos. 12, The Eeceptaculum Chyli : sev- 

 eral Lymphatic Trunks are seen opening into it. 13, The Thoracic Duct dividing, op- 

 posite the Middle Dorsal Vertebra, into two branches, which soon re-unite ; the course 

 of the Duct behind the Arch of the Aorta and Left Sub-Clavian Aorta is shown by a 

 Dotted Line. 14, The Duct making its turn at the Root of the Neck and receiving sev- 

 eral Lymphatic Trunks previous to terminating in the Posterior Angle of the Junction 

 of the Internal JnguTar and Sub-Clavian Veins. 15, The Termination of the Trunk of 

 the Lymphatics of the Upper Extremity. 



308. Where do the Lacteals besrin, and where do they terminate ? What do they re- 

 semble, and what do they pass through ? State the size of the Thoracic Duct, its course 

 and termination. 



