The digestive system breaks down food into absorbable components through a long muscular tube called the alimentary canal, extending from the mouth to the anus. Accessory organs like the liver, gallbladder and pancreas release secretions into the canal to aid in digestion. Food is mechanically and chemically broken down as it passes through sections of the canal like the mouth, esophagus, stomach, small and large intestines before leftovers are excreted as waste.