The stomach is a vital part of the digestive process in animals. The digestive system and the stomach work together to break down food, absorb the parts that are useful and move the rest through the remaining organs and out the anus. In this line of twisted and interconnected organs, the stomach lies between the esophagus and the small intestine.
In order to absorb nutrients and create energy, the body must break down food. The digestive system and the stomach do this through the secretion of acids and enzymes. Food travels from the mouth to the esophagus, then to the stomach and small intestine, then to the large intestine or colon, and finally through the rectum and out the anus. All along the way, enzymes aid chemical reactions which absorb nutrients and turn carbohydrates into energy.
First, the salivary glands inside the mouth contain an enzyme which digests starch into smaller molecules. Then food is swallowed and enters the esophagus, passes through the esophageal sphincter and into the stomach. The digestive system and the stomach then go to work, moving and mixing the food within it.
Stomach acid breaks down food and the stomach produces an enzyme which absorbs protein. A very thick mucus layer protects the rest of the body from the acids in the stomach. Some digestive disorders, such as acid overproduction, can occur, causing the mucus layer to deteriorate. Another common disorder is acid reflux, where acid backs up into the esophagus which does not have a thick mucus layer for protection.
The stomach pushes the food mixture into the small intestine through a series of muscle contractions. Inside the small intestine, the food mixes with juices produced by the pancreas and liver. The food then moves into the large intestine where it becomes waste that then exits the body.
Disorders of the digestive system and the stomach can range from indigestion, also called dyspepsia, to gastritis or peptic ulcers. Since the stomach is such a vital organ for the digestive process, such conditions can wreak havoc on blood sugar levels, appetite and a host of other functions. A gastroenterologist studies disorders of the digestive system and the stomach.
Cattle, sheep, goats, pigs and other animals have what is known as a ruminant digestive system. A common myth is that these animals have more than one stomach, which is otherwise known as polygastric. Instead, these animals have a very large stomach that is broken up into four compartments: the reticulum, omasum, rumen and abomasum.