The true stomach of ruminants is called abomasum. The stomach of a ruminant consists of four compartments: rumen, reticulum, omasum, and abomasum. The abomasum is also known as the "true stomach" because it is the compartment that is most similar to the stomach of non-ruminant animals, such as humans. It is the fourth and final chamber of the stomach and is responsible for digesting food with the help of enzymes and acids. It is also the site where proteins are broken down into amino acids, which can then be absorbed into the bloodstream.