CHAPTER VII. 



ON THE LYMPHATICS. 



THE lymphatic vessels, or absorbents, have received their double 

 appellation from certain phenomena which they present ; the former 

 name is derivable from the peculiar limpid fluid (lympha, water,) 

 which they convey ; and the latter, from their supposed property 

 of absorbing foreign substances into the system. They are minute 

 and delicate vessels, having a knotted appearance, and are distri- 

 buted through every part of the body. Their office is to collect 

 the products of digestion, and the detrita of nutrition, and to convey 

 them into the venous circulation near to the heart. 



Lymphatic vessels commence in a delicate network which is dis- 

 tributed upon the cutaneous surface of the body, upon the various 

 surfaces of organs and throughout their internal structure ; and 

 from this network the lymphatic vessels proceed, nearly in straight 

 lines, in a direction towards the root of the neck. In their course 

 they are intercepted by numerous small oval or rounded bodies 

 lymphatic glands in which the entering or inferent vessels ramify 

 to an extreme minuteness, and from which proceed the escaping or 

 efferent vessels somewhat larger in size and fewer in number, to be 

 again and again subdivided into other glands, and each time to be 

 a little more increased in size. 



Lymphatic vessels admit of a threefold division into superficial, 

 deep, and lacteals. The superficial lymphatic vessels, upon the sur- 

 face of the body, follow the course of the veins, and pierce the 

 deep fascia in convenient situations, to join the deep lymphatics. 

 Upon the surface of organs they converge to the nearest lymphatic 

 trunks. 



The Superficial lymphatic glands are placed in the most protected 

 situations of the superficial fascia, as in the hollow of the ham and 

 groin in the lower extremity, and upon the inner side of the arm in 

 the upper extremity. The deep lymphatics accompany the deeper 

 veins ; those from the lower parts of the body converging to the 

 numerous glands seated around the iliac veins and inferior vena 

 cava, and terminating in a large trunk situated upon the vertebral 

 column the thoracic duct. From the upper part of the trunk on 

 the left side, and from the left side of the head and neck, they also 

 proceed to the thoracic duct. Those on the right side of the head, 

 and neck, right upper extremity, and right side of the thorax, form 

 a distinct duct which terminates at the point of junction of the sub- 



