ANATOMY

From the confluence of right and left Lumbar Trunks (union of Efferent Vessels from Lateral Aortic Lymph glands) and Intestinal Trunk (receives lymph from stomach, intestines, pancreas, spleen, and lower part of liver) they are formed from Lymph Ducts in Abdomen. They form an important passage upward known as Cisterna Chyli (dilated sac at the lower end of thoracic duct). The Thoracic Duct extends into the chest vertically curving posteriorly to the left Carotid Artery and left Internal Jugular Vein at the vertebral level C7.

FUNCTION

In the Thoracic Duct the lymph is transported mainly by the action of breathing. The transport is aided by the smooth muscles of duct and internal valves which prevent the flowing back of lymph. To prevent the flow of venous blood in the Thoracic Duct two valves are present at the junction of duct. Thoracic duct transports almost 4 liters of lymph per day. The thoracic duct is 38 to 45 cm in length and 5 mm in diameter.

CLINICAL SIGNIFICANCE

The first sign of disease mainly the Intraabdominal is enlarged Virchow’s Node. It is lymph node in the left Supraclavicular area where the Thoracic Duct empties in the left Brachiocephalic Vein. The blockage of Thoracic Duct causes the large amount of lymph to accumulate in the Pleural Cavity (potential space between Visceral and Parietal pleurae of the lungs). The condition is known as Chylothorax.