Stomach : the internal organ in which the major part of the digestion of food occurs, being (in humans and many mammals) a pear-shaped enlargement of the alimentary canal linking the oesophagus to the small intestine. Molars : a grinding tooth at the back of a mammal's mouth. Chest : the front surface of a person's or animal's body between the neck and the stomach. Throat : the passage which leads from the back of the mouth of a person or animal. Gullet : the passage by which food passes from the mouth to the stomach; the oesophagus.