Conduit thoracique

In human anatomy, the thoracic duct (also known as the left lymphatic duct, alimentary duct, chyliferous duct, and Van Hoorne's canal) is the larger of the two lymph ducts of the lymphatic system (the other being the right lymphatic duct). The thoracic duct usually begins from the upper aspect of the cisterna chyli, passing out of the abdomen through the aortic hiatus into first the posterior mediastinum and then the superior mediastinum, extending as high up as the root of the neck before descending to drain into the systemic (blood) circulation at the venous angle. The thoracic duct carries chyle, a liquid containing both lymph and emulsified fats, rather than pure lymph. It also collects most of the lymph in the body other than from the right thorax, arm, head, and neck (which are drained by the right lymphatic duct). When the duct ruptures, the resulting flood of liquid into the pleural cavity is known as chylothorax. In adults, the thoracic duct is typically 38–45 cm in length and has an average diameter of about 5 mm. The vessel usually commences at the level of the twelfth thoracic vertebra (T12) and extends to the root of the neck before descending to terminate at the venous angle. The thoracic duct commences at the upper extremity of the cisterna chyli at the level of the T12 vertebra. Abdomen From its origin at the cisterna chyli, the thoracic duct ascends anterior to and to the right of the vertebral column, siuated in between the aorta, and the azygos vein. The thoracic duct traverses the diaphragm at the aortic hiatus to enter the posterior mediastinum. Posterior mediastinum It ascends the posterior mediastinum between the descending thoracic aorta (to its left) and the azygos vein (to its right), and is situated posterior to the esophagus at the T7 vertebral level. It crosses the midline to the left side at about the T5 level, continuing to ascend. It then passes posterior to the aorta, and to the left of the oesophagus. Superior mediastinum The thoracic ducts ascends into the superior mediastinum, reaching 2-3cm superior to the clavicle, as high up as the C7 vertebral level.