Henry Gray (18251861). Anatomy of the Human Body. 1918.
which accompany the posterior branches of the intercostal arteries, end in the intercostal glands. Those of the Intercostales interni and parietal pleura consist of a single trunk in each space. These trunks run forward in the subpleural tissue and the upper six open separately into the sternal glands or into the vessels which unite them; those of the lower spaces unite to form a single trunk which terminates in the lowest of the sternal glands. 3. The lymphatic vessels of the diaphragm, which form two plexuses, one on its thoracic and another on its abdominal surface. These plexuses anastomose freely with each other, and are best marked on the parts covered respectively by the pleuræ and peritoneum. That on the thoracic surface communicates with the lymphatics of the costal and mediastinal parts of the pleura, and its efferents consist of three groups: (a) anterior, passing to the gland which lie near the junction of the seventh rib with its cartilage; (b) middle, to the glands on the esophagus and to those around the termination of the inferior vena cava; and (c) posterior, to the glands which surround the aorta at the point where this vessel leaves the thoracic cavity.
The plexus on the abdominal surface is composed of fine vessels, and anastomoses with the lymphatics of the liver and, at the periphery of the diaphragm, with those of the subperitoneal tissue. The efferents from the right half of this plexus terminate partly in a group of glands on the trunk of the corresponding inferior phrenic artery, while others end in the right lateral aortic glands. Those from the left half of the plexus pass to the pre- and lateral aortic glands and to the glands on the terminal portion of the esophagus.
The visceral lymph glands consist of three groups, viz.: anterior mediastinal, posterior mediastinal, and tracheobronchial.
The Anterior Mediastinal Glands (lymphoglandulæ mediastinales anteriores) are placed in the anterior part of the superior mediastinal cavity, in front of the aortic arch and in relation to the innominate veins and the large arterial trunks which arise from the aortic arch. They receive afferents from the thymus and pericardium, and from the sternal glands; their efferents unite with those of the tracheobronchial glands, to form the right and left bronchomediastinal trunks.
The Posterior Mediastinal Glands (lymphoglandulæ mediastinales posteriores) lie behind the pericardium in relation to the esophagus and descending thoracic aorta. Their afferents are derived from the esophagus, the posterior part of the pericardium, the diaphragm, and the convex surface of the liver. Their efferents mostly end in the thoracic duct, but some join the tracheobronchial glands.
The Tracheobronchial Glands(Fig. 622) form four main groups: (a) tracheal, on either side of the trachea; (b) bronchial, in the angles between the lower part of the trachea and bronchi and in the angle between the two bronchi; (c) bronchopulmonary, in the hilus of each lung; and (d) pulmonary, in the lung substance, on the larger branches of the bronchi. The afferents of the tracheobronchial glands drain the lungs and bronchi, the thoracic part of the trachea and the heart; some of the efferents of the posterior mediastinal glands also end in this group. Their efferent vessels ascend upon the trachea and unite with efferents of the internal mammary and anterior mediastinal glands to form the right and left bronchomediastinal trunks. The right bronchomediastinal trunk may join the right lymphatic duct, and the left the thoracic duct, but more frequently they open independently of these ducts into the junction of the internal jugular and subclavian veins of their own side.
In all town dwellers there are continually being swept into these glands from the bronchi and alveoli large quantities of the dust and black carbonaceous pigment that are so freely inhaled in cities. At first the glands are moderately enlarged, firm, inky black, and gritty on section; later they enlarge still further, often becoming fibrous from the irritation set up by the minute foreign bodies with which they are crammed, and may break down into a soft slimy mass or may calcify.