CHAPTER XIII 

 ABSORPTION 



ABSORPTION is the process whereby the nutritive 

 material, lymph, is transferred from the tissues; the 

 serous cavities pericardium, peritoneum, etc.; and 

 mucous membranes into the blood. The lymph is 

 absorbed from the mucous membrane of the alimen- 

 tary canal, as it is the principal source of nutritive 

 material used by the body for the maintenance of 

 the quantity and quality of the blood; while the 

 lymph absorbed from the serous cavities and tissues 

 represents a reabsorption of the nutritive materials 

 which have escaped through the capillary walls, and 

 are returned to the veins through the lymphatic 

 vessels. Were this lymph allowed to collect in the 

 tissues, there would occur an excessive accumulation, 

 and this condition would be readily accounted for in 

 the swelling of the subcutaneous tissue and organs 

 giving rise to a pathologic condition termed edema. 



Under the chapter on digestion it was shown how 

 the food we eat is reduced to a liquid condition by 

 the action of the various gastric, pancreatic, and 

 intestinal juices and their ferments. This nutritive 

 material is taken up by the mucous membrane of 

 the intestine and absorbed, then reaches the blood- 

 current by way of the lymph channels lacteals, and 

 finally reaches the thoracic duct; or by way of the 

 venous capillaries of the mesenteric veins, and is carried 

 to the liver, and thence to the right side of the heart. 



Before understanding the methods of food absorp- 

 tion, a description of the mucous membrane of the 

 intestines is necessary. 



