APPLIED PHYSIOLOGY 



blood, while all the veins, excepting the pulmonary veins, carry dark 

 red or venous blood. 



310. The lymph. In order to nourish the body, the 

 plasma of the blood is continually being diffused through 

 the capillaries into the spaces between the living cells. 

 Each cell is thus bathed in a plentiful supply of plasma, 

 from which it absorbs its nutriment. The spaces also 

 contain many white cells, which have left the capillaries. 

 The blood plasma and blood cells filling the spaces be- 

 tween the cells are called the lymph, and the spaces are 

 called lymph spaces. 



The lymph is a thin, colorless fluid. In fact, it is blood 

 without the red corpuscles, but with many waste matters 

 from the cells of the body added. The lacteals of the 



intestine are also 

 lymphatics which 

 carry the digested 

 fats, and hence 

 their lymph is of a 

 milky-white color. 

 311. Lymphatics. 

 Lymph is con- 

 tinually collecting, 

 and its removal is 

 provided for by 

 means of a set of 

 tubes, called the 

 lymphatics. The 

 smallest lymphatic 

 tubes are much 

 smaller than a capillary, and their walls are so thin that 

 they can scarcely be seen with a microscope. Each begins 

 in the open space between a capillary and a cell of the 



Lymphatics of the head and neck. 

 B thoracic duct. 



