O o o . . .
t h e   s t o m a c h !

s t o m a c h

Ever wonder where the stomach is?
The stomach is in the gastrointestinal tract between the esophagus and the intestines.

Ooo... here are some physical features of it...
Your stomach is capable of altering its size and shape depending on the position of the body and the amount of food inside. It is about 12 in. (30.5 cm) long and 6 in. (15.2 cm) wide at its widest point. Its capacity is about 1 qt (0.94 liters) for adults.

What happens to the food again??
The stomach has the job of mashing up the food we eat and turning it into a soupy paste (like blended vegetable soup - not the chunky variety). The stomach can do this because it has three layers of muscles contracting in different directions. Between the stomach and the small intestine is a tight muscle. It is only when this muscle relaxes that food can leave the stomach to continue through the digestive system. When it relaxes, a small amount of food is squeezed into the small intestine before the muscle tightens again, sealing off the tube. The rest of the food stays in the stomach until the small intestine is ready for it. The removal of food from the stomach stops the stomach from filling up completely.

Is that all what the stomach does?
Your stomach functions primarily as storage and mixing chamber for ingested food, which typically remains in the stomach for one to four hours. Although some digestion and a small amount of absorption occur in the stomach, the main role of the stomach is to mix the food with gastric juices to make a semi-fluid mixture called chyme. The stomach does this through the contractions of the stomach wall's smooth muscles that contract to mix the food with the gastric secretions. The contractions also force small amounts of the chyme past the pyloric sphincter (a thick layer of smooth muscle which surrounds the opening from the stomach into the small intestine) into the small intestines for the next stage of digestion.

s t o m a c h   q u i z

Test your knowledge on the stomach. Click on next to start the quiz, or move on to the next section to skip the quiz.