FACTS: The stomach receives, holds and partly digests food. This pouch-like organ is actually small, but as you eat the stomach wall quickly stretches to hold up to 3/4 gallon or 3 liters. It churns and mixes food with acids and enzymes. The powerful muscles lining the stomach mash food, breaking up fats and proteins. Orange juice… how about some stomach juice?! When you see or smell food, tiny stomach glands secrete gastric juice. This stomach juice is mostly hydrochloric acid with a touch of the enzyme pepsin that digests proteins. The acid activates pepsin, breaks down food, and also kills germs. Your stomach produces up to 3 liters of gastric juice every day. Mucous cells that line the stomach protect it from the acid, so that the stomach doesn’t digest itself!
Compared to other creatures, the human stomach is not too exciting. The blue whale’s stomach can hold 2,000 pounds of food. The cow’s stomach is divided into four distinct sections that hold grass-chomping microbes. The jellyfish’s gastric cavity converts food into a soupy liquid that’s transferred directly into its circulatory system; leftovers are expelled back out of the jellyfish’s stomach the same way they came in. Or how about the python’s stomach, which can stretch enormously to hold a fully intact, 80-pound deer!