The digestive process begins in the mouth. Chewing breaks food into smaller pieces, increasing the surface area available to enzymes. Saliva contains the enzyme amylase, which breaks down starch into small sugar molecules. In the mouth, saliva and mucus blend with the food to form a Choose...boluschymesphincterepiglottis. This ball of chewed food then slides through the esophagus to the stomach. Once in the stomach the Choose...epiglottisesophageal sphincterpyloric sphincterjejunum keeps the food from sliding back into the esophagus. Choose...Intrinsic factorGastrinPepsinHydrochloric acid creates an acidic environment in the stomach that kills many pathogenic bacteria and aids in the digestion of protein. When the chyme is ready to leave the stomach, about 30-40 percent of carbohydrate, 10-20 percent of protein, and less than Choose...5%10%20%30% of fat have been digested. Choose...Very littleAlmost allNoAbout half of total absorption occurs in the stomach. In the small intestine most digestion takes place in the Choose...jejunumduodenumileumlacteals. Fats do not ususally mix with water but this process is facilitated by Choose...cholecystokininpancreatic lipasebilesecretin once it is released from the gallbladder into the duodenum. Nutrients absorbed through the intestinal lining pass into the interior of the villi. Each villus contains blood vessels and a Choose...lactealileocecal valvemicrovillienteric nerve. Most minerals with the exception of Choose...potassiumsodiumchlorideall of the above are absorbed in the small intestine. Undigested material and some liquid move on to the Choose...small intestinelarge intestinestomachliver, where water and electrolytes are absorbed, leaving waste material to be excreted as feces.