Stomach the small intestine, where the extraction of nutrients begins. Depending on the quantity and contents of the meal, the stomach will digest the food into chyme within anywhere between forty minutes and a few hours. The average human stomach can comfortably hold about a litre of food. Gastric juice in the stomach also contains pepsinogen. Hydrochloric acid activates this inactive form of enzyme into the active form, pepsin. Pepsin breaks down proteins into polypeptides. Although the absorption in the human digestive system is mainly a function of the small intestine, some absorption of certain small molecules nevertheless does occur in
Monogastric the food enters the mouth. Saliva moistens the food and begins the digestive process. (Note that horses have no (or negligible amounts of) amylase in their saliva). After being swallowed, the food passes from the esophagus into the stomach, where stomach acid and enzymes help to break down the food. Bile salts are stored in the gall bladder (note that horses do not have a gall bladder and bile is directly secreted into the small intestine) and secreted once the contents of the stomach have reached the small intestines where most fats are broken down. The pancreas secretes enzymes and