THE WORK OF THE STOMACH
It is in the stomach, on the other hand, that most of the work of digesting the albuminoids, or proteids, of food is performed by the gastric juice. The stomach is a pear-shaped bag, that holds about three pints of material, or three-quarters of an ounce for every inch of the individual’s height. Food enters it through the gullet on the upper left hand side, just below the heart. Myriads of glands in the walls of the stomach are active in the formation of either pepsin, or an acid fluid which, when combined with pepsin, forms the gastric juice.
At the back of the stomach, partly overlapping it, lies the liver, which discharges a liquid called the bile into the alimentary canal just below the stomach. Behind the stomach, lies a large gland called the pancreas, which discharges a remarkable fluid, named pancreatic juice, into the intestine through the same opening which the liver uses for its bile. Connected with the stomach is the small intestine, which is the narrow portion of the alimentary canal, and the largest and most important of all the digestive organs. It is some twenty-five feet in length, and its walls are everywhere covered with glands which secrete and exude mucous and other fluids.
At the lower end of the intestine is the colon or large intestine which is not a digestive organ in itself, but is a reservoir in which the food is stored up for a short time, to allow opportunity for complete absorption of the digested portions.