LYMPHATICS OF THE THORAX.-UPPER LIMB. 497 



Their number is considerable, but they are sometimes difficult of demon- 

 stration. The deep lymphatics run with the pulmonary blood-vessels. 

 Both superficial and deep lymphatics converge to the root of the lung, and 

 terminate in the bronchial glands. From these, two or three trunks issue, 

 which ascend along the trachea to the root of the neck, and terminate on 

 the left side in the thoracic duct, and on the right in one of the right 

 lymphatic trunks. 



The lymphatics of the heart follow the coronary arteries and veins from 

 the apex of the organ towards the base, where they communicate with each 

 other, and those of each side are gathered into one trunk. The trunk from 

 the right side, running upwards over the aortic arch between the innominate 

 and left carotid arteries to reach the trachea, ascends to the root of the 

 neck, and terminates in the right lymphatic duct. The vessel from the left 

 side proceeding along the pulmonary artery to its bifurcation, passes through 

 some lymphatic glands behind the arch of the aorta, and ascends by the 

 trachea to terminate in the thoracic duct. 



The lymphatics of the oesophagus, unlike those of the rest of the alimentary 

 canal, form only one layer, which lies internal to the muscular coat. They 

 are connected with glands in the neighbourhood, and after having com- 

 municated by anastomoses with the lymphatics of the lungs, at and near 

 the roots of those organs, they terminate in the thoracic duct. 



The lymphatics of the thymus gland are numerous. According to Astley 

 Cooper, two large vessels proceed downwards from them on each cornu, and 

 terminate in the jugular veins by one or more orifices on each side. 

 (Anatomy of the Thymus Gland, p. 14.) 



LYMPHATICS OF THE UPPER LIMB, 



AND OF THE BREAST AND BACK. 



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 lymphatics 

 of the surface of the greater part of the back, and those of the mamma and 

 pectoral muscles, 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 even of the arteries of the forearm ; and one or more small glands 

 are found in connection with the superficial lymphatics, lying 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 ten or twelve in number : they vary, 

 however, considerably in their number as well as in their size, in different in- 

 dividuals ; they are mostly placed along the axillary vessels, the lower member 

 of this group receiving the lymphatics which ascend from the limb ; but a few 

 lie further forwards on the serratus magnus near the external mammary 

 artery, and beneath the pectoral muscles, and receive lymphatics from the 

 mamma and muscular walls of the chest ; while others incline downwards at 

 the posterior boundary of the axilla, and are joined by the lymphatics from 

 the back. 



From the glands of the axilla efferent lymphatic vessels, fewer in number, 

 but larger in size than the afferent vessels, proceed along the course of the 

 subclavian artery, in some parts twining round it. From the top of the 

 thorax they ascend into the neck, close to the subclavian vein, and terminate, 

 those of the left side in the thoracic duct, those of the right side 



