The thoracic duct
Lymph from the legs, the pelvis and the gut passes the nodes beside the aorta and gathers in a sac a few centimetres long, the cisterna chyli. It lies in front of the first two lumbar vertebrae, beside the abdominal aorta. From its top rises the thoracic duct, the largest lymph vessel in the body, 38 to 45 cm long.
The duct passes through the diaphragm with the aorta and climbs the back of the chest between the descending aorta and the azygos vein. Near the fifth thoracic vertebra it crosses to the left, rises into the root of the neck and arches over to end at the left venous angle, where the internal jugular and subclavian veins meet.
The thoracic duct rising from the cisterna chyli among the lumbar nodes, up the back of the chest beside the oesophagus to the left internal jugular and subclavian veins, with the right lymphatic duct on the other side, Gray's Anatomy, 1918, figure 599Wikimedia Commons, Henry Vandyke Carter, Public domain (Gray599.png)
It carries the lymph of three quarters of the body, about 100 ml an hour at rest. A valve at its mouth keeps blood out.
Sources
- Susan Standring (ed.), Gray's Anatomy, 42nd ed. (2020), chapter on the mediastinum.
- Arthur Guyton and John Hall, Textbook of Medical Physiology, 13th ed. (2016), ch. 16.
- Henry Gray, Anatomy of the Human Body, 20th ed. (1918), section VIII, The Thoracic Duct.
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