The solid organs -- pancreas, liver, and gallbladder -- add various products into the mix.Enter your email Your privacy is important to us The journey of digestion In humans, the gastrointestinal tract (also called the alimentary canal) is around 8 meters long.Aside from the solid and hollow organs, the nervous and circulatory systems are also important in digestion, as are the bacteria that live in the gut.Get our free daily newsletter Expect in-depth, science-backed toplines of our best stories every day.Chemical digestion -- food is broken down by acids and enzymes into its basic units.Digestion is often broken down into two types: Mechanical digestion -- food is physically broken into smaller parts.For instance, by chewing.MEDICAL NEWS TODAY NEWSLETTER Stay in the know.Tap in and keep your curiosity satisfied.