The<unk>  is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The<unk>  has a dilated structure and functions as a vital digestive organ. In the digestive system the<unk>  is involved in the second phase of digestion, following chewing. It performs a chemical breakdown by means of enzymes and hydrochloric acid. In humans and many other animals, the<unk>  is located between the oesophagus and the small intestine. The<unk>  secretes digestive enzymes and gastric acid to aid in food digestion. The pyloric sphincter controls the passage of partially digested food (chyme) from the<unk>  into the duodenum, where peristalsis takes over to move this through the rest of intestines.
Stomach
Large intestine
Small intestine
Gastrointestinal tract
Heart
Liver
Lung
Venom