The stomach is a muscular, hollow, dilated part of the digestion system which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects ,and molluscs. It is involved in the second phase of digestion, following mastication .
The stomach is located between the esophagus and the small intestine. It secretes protein-digesting enzymes called proteases and strong acids to aid in food digestion, through smooth muscular contortions before sending partially digested food to the small intestines.
