Lymphatic vessels and nodes of the thoracic cavity

In the chest cavity, there are parietal (parietal) lymph nodes, located on the corresponding walls (anterior, inferior and posterior), and visceral (visceral), located in the chest cavity on the paths of lymph flow from its internal organs.

Parietal (wall) lymph nodes are the parasternal lymph nodes (nodi lymphatici parasternales), no. 2-20 on each side. They are located on the inner (back) surface of the anterior chest wall to the right and left of the sternum and are adjacent to the internal thoracic arteries and veins; in rare cases, single nodes are located on the back surface of the sternum. The parasternal lymph nodes receive lymphatic vessels not only from the tissues of the anterior chest wall, pleura and pericardium, lower epigastric and upper diaphragmatic lymph nodes, but also from the diaphragmatic surface of the liver (penetrate the diaphragm) and from the mammary gland. The efferent lymphatic vessels of the right parasternal lymph nodes flow into the right jugular trunk and into the prevenous lymph nodes located in the upper mediastinum. The vessels of the left parasternal nodes are directed to the pre-aortic lymph nodes and also flow directly into the thoracic duct and into the left jugular trunk.

In the intercostal spaces on each side of the spinal column, near the posterior intercostal vessels, are located the posterior intercostal lymph nodes (nodi lymphatici intercostales, 1-7 in total). Lymphatic vessels from the posterior wall of the chest cavity are directed to these nodes. The efferent lymphatic vessels of the intercostal nodes flow into the thoracic duct, and from the upper nodes - into the deep lateral cervical (internal jugular) lymph nodes located near the internal jugular vein.

The superior diaphragmatic lymph nodes (nodi lymphatici phrenici superiores) are located on the diaphragm, to the left of the inferior vena cava and around the pericardium, at the points where the right and left phrenic nerves and muscular-phrenic arteries enter the diaphragm. Depending on their position relative to the pericardium, this group includes inconstant lateral pericardial, prepericardial and retropericardial lymph nodes. Paired lateral pericardial nodes (nodi lymphatici pericardiales laterales, 1-4 on the right and 1-2 on the left) are more common (in 50% of cases) near the right phrenic nerve than near the left (10%). The prepericardial lymph nodes (nodi lymphatici prepericardiales, 1-7 in total) are located behind the xiphoid process and near the muscular-diaphragmatic arteries where they enter the diaphragm. The retropericardial lymph nodes (1-9) are located under the pericardium, near the inferior vena cava and in front of the esophagus. The diaphragmatic nodes receive lymphatic vessels from the diaphragm, pericardium, pleura and diaphragmatic surface of the liver (they pierce the diaphragm). The efferent lymphatic vessels of the superior diaphragmatic lymph nodes flow mainly into the parasternal, posterior mediastinal, inferior tracheobronchial and bronchopulmonary lymph nodes.

The visceral (internal) lymph nodes include the anterior and posterior mediastinal, tracheobronchial and bronchopulmonary lymph nodes. The anterior mediastinal lymph nodes (nodi lymphatici mediastinales) are located in the upper mediastinum (in the upper part of the anterior mediastinum), on the anterior surface of the superior vena cava and brachiocephalic veins, the aortic arch and the arteries branching off from it, upward from the base of the heart. According to their position, these nodes (according to Rouvier-Zhdanov) are divided into precaval (prevenous) lymph nodes (1-11), which lie in front of the superior vena cava and right brachiocephalic veins; preaortocarotid (3-18), located on the anterior surface of the left brachiocephalic vein and brachiocephalic trunk.

The anterior mediastinal lymph nodes receive the lymphatic vessels of the heart, pericardium, thymus, and the efferent lymphatic vessels of the bronchopulmonary and tracheobronchial lymph nodes. Several fairly large lymphatic vessels emerge from the lymph nodes located in the upper and anterior parts of the mediastinum and head upwards into the neck region - to the right and left venous angles. The efferent lymphatic vessels of the prevenous lymph nodes form a small-diameter short right lymphatic duct (truncus lymphaticus dexter), which occurs in Va cases, as well as into the right lymphatic duct or into the right jugular trunk and peribronchial lymph nodes. The efferent lymphatic vessels of the preaortocarotid nodes flow into the thoracic duct, the left jugular trunk, and also go to the left lateral (internal) jugular lymph nodes. Thus, lymph from the lymph nodes of the anterior (superior) mediastinum can flow toward either the right or left venous angle.

The posterior mediastinal lymph nodes (nodi lymphatici mediastinales posteriores, 1-15 in total) are located in the tissue near the thoracic aorta and near the esophagus, and receive lymph from the organs of the posterior mediastinum. The lymph nodes lying near the esophagus (in front of it) and on the sides - paraesophageal, as well as those located between the aorta and esophagus - interaortoesophageal (1-8), are found in approximately 60% of cases. Behind the aorta and to the side of it, the paraaortic lymph nodes are found even less often - in less than 30% of cases. The efferent lymphatic vessels of these nodes flow directly into the thoracic duct, as well as into the lower tracheobronchial and, rarely, into the left extraorgan bronchopulmonary lymph nodes.

Bronchopulmonary lymph nodes lie along the paths of the lymphatic vessels of the lung, 4-25 in total. Intraorgan bronchopulmonary nodes are located in each lung at the sites of branching of the main bronchi into lobar and lobar into segmental, and extraorgan (root) ones are grouped around the main bronchus, near the pulmonary arteries and veins. The efferent lymphatic vessels of the right and left bronchopulmonary nodes are directed to the lower and upper tracheobronchial lymph nodes. Sometimes they flow directly into the thoracic duct, as well as into the prevenous nodes (on the right) and preaortocarotid (on the left).

The lower tracheobronchial (bifurcation) lymph nodes (nodi lymphatici tracheobronchiales inferiores, 1-14 in total) lie beneath the bifurcation of the trachea, and the upper tracheobronchial (right and left) lymph nodes (nodi limphatici tracheobronchiales superiores dextri, 3-30, et sinistri, 3-24) are located on the lateral surface of the trachea and in the tracheobronchial angle formed by the lateral surface of the trachea and the upper semicircle of the main bronchus of the corresponding side. The efferent lymphatic vessels of the bronchopulmonary nodes, as well as other visceral and parietal nodes of the thoracic cavity, are directed to these lymph nodes. The efferent lymphatic vessels of the right upper tracheobronchial nodes participate in the formation of the right bronchomediastinal trunk and the right lymphatic duct. There are also pathways for lymph drainage from the right upper tracheobronchial lymph nodes toward the left venous angle. The efferent lymphatic vessels of the left upper tracheobronchial lymph nodes flow into the thoracic duct.

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