What Is the Thoracic Duct?

The thoracic duct is the longest lymphatic duct in the body. Lymphatic fluid was collected from the left half of the body, the abdomen, and both lower extremities. The thoracic duct generally forms an initial part in front of the first 1-2 lumbar vertebrae. Perforate the diaphragmatic aorta into the chest cavity and inject it into the left vein. If blockage or rupture occurs, it can cause chylothorax and chylotomy abdomen.

The thoracic duct is the longest lymphatic duct in the body. Lymphatic fluid was collected from the left half of the body, the abdomen, and both lower extremities. The thoracic duct generally forms an initial part in front of the first 1-2 lumbar vertebrae. Perforate the diaphragmatic aorta into the chest cavity and inject it into the left vein. If blockage or rupture occurs, it can cause chylothorax and chylotomy abdomen.

Chinese name

Thoracic duct

Foreign name

thoracic duct

Thoracic duct anatomy:

1. Thoracic duct:

The thoracic duct is the largest lymphatic vessel in the body, also known as the left lymphatic duct. The total length is about 30 to 40 centimeters, and it is generally made up of the left and right lumbar trunks and intestinal trunks in front of the 1st to 2nd lumbar vertebrae. The beginning is swollen and is called chyle pond. After the start of the thoracic duct, close to the front of the spine, go up the right and back of the abdominal aorta, penetrate the aortic hiatus into the posterior mediastinum of the thorax, and continue to go up the right front of the spine to the 5th thoracic spine through the aortic arch and esophagus The back of the spine is obliquely turned to the left front of the spine, and then rises along the left side of the esophagus, exits the upper opening of the thorax to the root of the neck, and bends into the left venous angle in an arcuate direction. . Before the venous angle was injected, the thoracic duct received the left neck shaft, subclavian shaft, and left bronchial mediastinal shaft. The three stem entrances are generally free of valves, which is one of the important factors for cancer cells to metastasize to the lymph nodes at the root of the neck through a thoracic duct when tumors in the thoracic and abdominal organs are affected by tumors.

The thoracic duct collects the lymph on the left upper body and the entire lower body, that is, the lymph in the 3/4 area of the human body flows into the vein through the thoracic duct.

2. Lymphatic duct:

The lymphatic duct is the terminal part of the lymphatic system. There are two lymphatic ducts, which are composed of nine lymphatic trunks. The right cervical trunk, right subclavian trunk, and right bronchial mediastinal trunk are combined into a right lymphatic duct; the left cervical trunk, left subclavian trunk, left bronchial mediastinal trunk, intestinal trunk, and left and right lumbar trunks are combined into a chest catheter (left lymphatic duct ) The right lymph duct is injected into the right venous corner, and the thoracic duct is injected into the left venous corner.

The wall structure of lymphatic vessels is similar to that of veins, but the three-layer structure is not as clear as that of large vein walls.

The morphological structure of thoracic duct and its surrounding structure:

Thoracic duct, also called "left lymphatic duct", is the longest and thickest lymphatic duct in the whole body. This catheter is 30 to 40 cm in length and collects lymphatics from two lower limbs, pelvic cavity, abdominal wall and its internal organs, left lung, left half heart, left chest wall, left upper limb, and left half head. The lower end of the thoracic duct starts from the swollen chylopool, which rises through the aortic hiatus into the thorax, and is connected to the medial foot of the iliac crest at the fissure, so the contraction of the horns during breathing can promote lymph flow. The thoracic duct is located behind the posterior mediastinal esophagus in the thorax, between the thoracic aorta and the odd vein, and rises along the front of the spine, moves to the left at the 4th and 5th thoracic vertebrae, and rises beyond the back of the aortic arch, bending at the 7th cervical spine It is arched sideways, and then into the left internal jugular vein or left venous corner, and 3 lymphatic stems are injected at the end.

Composition of thoracic duct and lymphatic duct:

Nine lymph trunks of the whole body merge into two large lymphatic vessels, namely the right lymphatic duct and the thoracic duct.

The right cervical trunk, right subclavian trunk, right bronchial mediastinal trunk were injected into the right lymphatic duct, the remaining 6 lymphatic trunks were injected into the thoracic duct, and two lymphatic ducts were injected into the left and right venous angles, respectively.

(A) chest duct

The thoracic duct is the largest lymphatic tube in the whole body, with a length of 30-40cm. The diameter of this tube is about 3mm. There are fewer valves in the lumen, and it takes up about 3/4 of the body's lymphatics.

Chylous pool is the initial expansion of the thoracic duct, which is usually located in front of the first lumbar spine, and is formed by the left and right lumbar trunk and intestinal trunk.

The thoracic duct ascends from the chyle pool to the front of the spine, passes through the iliac aortic fissure behind the aorta and enters the thoracic cavity. It continues upward after the esophagus and anterior to the spine, and deviates to the left near the 5th thoracic spine and exits the upper thorax to the root of the neck. Later, the forward bow is called the thoracic duct arch, and the top of the arch is about flat to the height of the 6th to 7th cervical vertebrae. Most of them continue to merge forward and downward into the left vein angle, and a few can be injected into the left internal jugular vein.

(Two) right lymphatic duct

The right lymph duct is a short trunk with a length of 1 to 1.5 cm and a diameter of about 2 mm. It is formed by the confluence of the right neck trunk, right subclavian trunk, and right bronchial mediastinal trunk, and is injected into the right vein corner. Sometimes the three lymphatics do not converge, but are injected into the internal jugular vein or subclavian vein.

Thoracic duct and thoracic duct related diseases:

Thoracic duct injury:

Overview:

Chest trauma can cause thoracic duct rupture and chylous fluid to leak into the mediastinum or pleural cavity to produce chylothorax. The most common thoracic duct injuries are injuries during surgery, such as resection of the upper and middle esophageal cancer, major cardiac vascular surgery, and posterior mediastinal tumor removal, which can all damage the thoracic duct. Rupture of thoracic ducts due to penetrating or closed injuries is rare. The main symptom of thoracic duct injury is the loss of a large amount of chyle, which results in deficiencies in the nutritional body, and the other is that a large amount of chyle accumulates in the chest cavity to compress the heart and lungs and causes respiratory and circulatory insufficiency. Confirmation of the diagnosis requires thoracentesis to extract the pleural fluid for examination. After adding ether, the pleural fluid is clarified, or orange yellow fat globules are observed under the microscope after staining with Sudan III to confirm the diagnosis. Small thoracic duct fractures can be cured by conservative treatment, including puncture and drainage or drainage of chest tube, supplementation of protein and nutrients, and promotion of pleural cavity adhesion. If the amount of chyle ineffective in conservative treatment does not decrease, a thoracotomy should be performed, the rupture of the thoracic duct should be found and sutured, and the thoracic duct should be ligated at the upper and lower ends.