1274 



THE ORGANS OF DIGESTION 



of the valve. The pylorus is normally kept closed by the action of this Sphincter 

 muscle. During the early stage of digestion it remains closed, but after a time 



Antrnm cardiacum. 

 Pyloric valve. 



Pylorus. 

 Pyloric canal. 



FIG. 995.-- Interior of the stomach. 



Cystic duct. 



FIG. 996. The mucous membrane of the stomach and duodenum with the bile-ducts. 



opens now and then, this relaxation becoming more frequent and the period of 

 patency more prolonged as digestion advances. 



