556 THE LYMPHATICS OF THE UPPER LIMB. 



trunks, which pass backwards, one on each side of the pulmonary artery, to the 

 concavity of the arch of the aorta, and there terminate in the glands at the bifurca- 

 tion of the trachea (Sappey) . 



The lymphatics of the lung, like those of the viscera generally, form two sets, 

 one being superficial, the other deep-seated. Those at the surface are numerous and 

 form a network beneath the pleura. The deep lymphatics run with the pulmonary 

 blood-vessels and the bronchial tubes. The vessels of both sets converge to the root 

 of the lung and terminate in the bronchial glands. 



The lymphatics of the oesophagus form only a single plexus between the 

 muscular and mucous coats. The trunks emerging from this plexus perforate the 

 muscular wall and terminate in the inferior cervical and posterior mediastinal glands. 



The lymphatics of the thymus gland are numerous and large. They enter 

 the glands of the superior mediastinum, and, according to Astley Cooper, two large 

 vessels proceed, one from each lateral lobe, to open by one or more orifices into the 

 internal jugular veins. 



LYMPHATICS OF THE UPPER LIMB. 



In the upper limb, as in the lower, the lymphatics are arranged in a deep and a 

 superficial set. These two sets of vessels, together with the superficial lymphatics 

 of the greater part of the back and of the chest, converge to the axillary glands. 



The lymphatic glands found in the upper limb below the axilla are neither large 

 nor numerous ; a few, however, are found in the course of the brachial artery, and 

 occasionally even of the arteries of the forearm ; two or more small glands are some- 

 times found in connection with the superficial lymphatics at the bend of the elbow, 

 and one or two, more constantly, near the commencement of the basilic vein, a 

 little above and in front of the inner condyle of the humerus. 



The axillary glands are generally twelve or more ; they vary much, however, 

 in their number, as well as in their size, in different individuals. From four to six 

 are placed along the axillary vessels, and receive the lymphatics which ascend from 

 the limb ; four or five small pectoral glands lie farther forwards on the serratus 

 magnus near the long thoracic artery, at the lower border of the pectoral muscles, and 

 receive the lymphatics from the mamma and front of the chest ; while three or 

 four subscapular glands are situated at the back of the axilla, along the subscapular 

 vessels, and are joined by the lymphatics from the back. One or two small infra- 

 clavicular glands are also found immediately below the clavicle in the hollow 

 between the pectoralis major and deltoid muscles ; they receive some lymphatics 

 from the outer side of the arm and the shoulder, and are connected above with the 

 inferior cervical glands, below with the axillary, glands. 



The efferent vessels of the axillary glands ascend with the subclavian vein, and 

 form by their union in some cases a single trunk (axillary lymphatic- trunk), in 

 others two or three large vessels, which terminate on the left side in the thoracic 

 duct, on the right side in the right lymphatic duct. Sometimes they open separately 

 into the subclavian vein near its termination. 



The superficial lymphatics of the upper limb begin in cutaneous networks, 

 which are closest and most developed on the fingers and in the palm of the hand. 

 The digital plexuses are finer and denser on the palmar than on the dorsal aspect, and 

 empty themselves on each side of the fingers into two or three collateral trunks, 

 which ascend to the back of the hand. From the network in the palm vessels con- 

 verge below to the interdigital spaces, where they turn backwards to pass with the 

 digital trunks to the dorsum of the hand, and others ascend over the front of the 

 wrist to the forearm. The numerous lymphatics passing up the forearm tend to form 

 three groups accompanying the radial, median and ulnar veins, the outer and inner 



