179 

 PART II.— THE LYMPHATIC SYSTEM. 



427. Intimately connected with the circulatory system, there is the 

 Lymphatic or Absorbent System, which is made up of numerous vessels, 

 of various sizes, and small bodies, also of different sizes, called glands. 

 The absorbents originate in a very fine network communicating with 

 fine delicate tubes, which are more numerous than the capillaries of 

 the blood-vessels, and are found in almost every structure of the 

 body, being both deep-seated and superficial. The walls of the larger 

 vessels have three coats, and, internally, they are supplied with valves 

 which gives them a beaded appearance when distended. 



428. A number of the smallest of these absorbent vessels (Afferent 

 Vessels) will be found running to the glands. These are present in 

 almost every portion of the body, and are of various sizes, being usually 

 named after the region in which they are found, for instance : the 

 mesenteric glands in connection with the intestines, and the bronchial 

 glands associated with the lungs. These glands give off other vessels 

 (Efferent Vessels) which are slightly larger, and these again pass to 

 other glands, and so on until they end in one or other of the two 

 large trunks, i.e., the thoracic duct and the right lymphatic vessel, the 

 former being the larger of the two. 



429. The Thoracic Duct carries a mixture of both lymph and chyle. 

 The lymph is a colourless fluid that is absorbed from the various 

 tissues of the posterior portion of the body and hind extremeties, also 

 from the left side of the head, neck, thorax, and left fore leg. The 

 chyle is a milky fluid that is prepared during the process of digestion, 

 and is taken up by the lacteals, or lymphatic vessels, and carried to 

 the receptaculum chyli, where it mixes wath the lymph, and is then 

 conveyed by the thoracic duct mto a vein near the heart (par. 224, Nos. 

 7 and 8). 



430. The Right Lymphatic Vessel is a receptacle for the lymph 

 that is taken up by the absorbents on the right side of the head, neck, 

 thorax, and right fore leg, and it empties itself into the venous blood- 

 stream near the heart, generally at the confluent vein of the jugulars. 



