Stomach

          The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects (mid-gut), and molluscs. It is involved in the second phase of digestion, following mastication (chewing).

          The stomach is located between the esophagus and the small intestine. It secretes protein-digesting enzymes and strong acids to aid in food digestion, (sent to it via oesophageal peristalsis) through smooth muscular contortions (called segmentation) before sending partially digested food (chyme) to the small intestines.

          The word stomach is derived from the Latin stomachus which is derived from the Greek word stomachos, ultimately from stoma, "mouth". The words gastro- and gastric (meaning related to the stomach) are both derived from the Greek word gaster.

The stomach is divided into four sections, each of which has different cells and functions. The sections are:

Cardia	Where the contents of the oesophagus empty into the stomach.
Fundus	Formed by the upper curvature of the organ.
Body or Corpus	The main, central region.
Pylorus	The lower section of the organ that facilitates emptying the contents into the small intestine.

FUNCTION:

          After food is chewed and moistened in the mouth, it passes through the esophagus into the stomach. This is the second step in the digestion of everything you consume. Food is mixed with stomach acid and enzymes to break the food down into smaller pieces. This combination of food and stomach "juices" is called chyme. The stomach also stores food temporarily, releasing chyme in small amounts into the small intestine, where it is further broken down into nutrients to be absorbed into the body.