122 



II. DIGESTION AND ABSORPTION OF FATS 



carry the chyle from the intestines to the cisterna chyli, and eventually to the 

 thoracic duct, from which the lymph is poured into the blood stream. 



In addition to the lymphatics, arteries also enter the villi. Only a single 

 artery is involved with each villus in the case of man and dog ; 2 or 3 arteries 

 occur in each villus in the case of the rat and the rabbit. The arteiy ex- 

 tends to the top of the villus, where it divides, part of it to form a capillary 



Ha lib 



Fig. 7. The Golgi apparatus (trophospongium) in the intestinal epithelium of rats 

 during fasting (I) and after a meal containing fat (II) 598 (/, fat droplets; ga, Golgi ap- 

 paratus; v, vacuole). 



network and part to establish direct connection with the main vein. In 

 the fasting animal, the blood passes only through the arteriovenous con- 

 nection. In man, there are fifteen to twenty capillaries which pass directly 

 under the epithelial layer; little nests of veins are also found in the sub- 

 mucosal layer. These veins provide a direct connection with the portal 

 blood supply, by way of which sugars, amino acids, salts, and other water- 

 soluble components are believed to pass to the liver ; only minimal amounts 

 of lipids are transported by this route. 



In addition to the mechanism whereby absorption of the foodstuffs is 

 effected, the intestinal mucosa also functions to produce an intestinal secre- 



