glossary

gastric juice

Definition gastric juice

gastric juice

gastric juice the liquid secreted by the *gastric glands of the stomach. Its main digestive constituents are hydrochloric acid, mucin, *rennin, and pepsinogen. The acid acts on pepsinogen to produce *pepsin, which functions best in an acid medium. The acidity of the stomach contents also kills unwanted bacteria and other organisms that have been injested with the food. Gastric juice also contains *intrinsic factor, which is necessary for the absorption of vitamin B12.