176 



ANATOMY FOR NURSES 



[ClL\P. X 



very little from 

 in the ordinary 



testinal digestion they are filled with chyle which has a white 

 aspect, dependent upon the fatty particles absorbed from the 

 food, and suspended in it like oil globules in milk. After fast- 

 ing, the lacteals contain lymph which differs 



the lymph found 

 lymphatics. 



Serous sacs. — A close relationship 

 exists between the lymphatics and 

 the serous membranes proper. These 

 closed sacs are to be regarded as 

 prodigiously expanded lymph spaces. 

 The true stomata of these serous mem- 

 branes are connected with other lymph 

 spaces. 



Function of the lymphatics. — The 

 function of the lymphatics is to carry 

 from the tissues to the veins all the 

 materials which the tissues do not 

 need. Functionally they may be con- 

 sidered between the capillaries and the 

 veins, as they gather up the lymph 

 which exudes through the thin capil- 

 lary walls, and return it to the innomi- 

 nate veins. Here it becomes mixed 

 with the blood, enters the superior 

 vena cava, and then the right auricle 

 of the heart. The function of the lacteals is to help in the ab- 

 sorption of digested food, especially fats. 



Lymph nodes. — The lymph nodes are numerous round or 

 ovoid bodies placed in the course of the lymphatics. They vary 

 in size from a pinhead to an almond. A lymph node is covered by 

 an envelope, or capsule, of connective and muscular tissue. This 

 capsule sends fibrous bands called trabeculae (little beams) 

 into the substance of the node, and divides it into irregular spaces, 

 which communicate freely with each other. The irregular spaces 

 are occupied by a mass of cellular pulp substance, which, however, 

 does not quite fill them as it never touches the capsule or trabeculae, 

 but leaves a narrow interval between itself and them. It looks as if 

 the pulp had originally filled the framework and then shrunk away 



Fig. 112. — A Lymph Node 

 WITH ITS Afferent and Effer- 

 ent Vessels. (Gerrish.) 



