Digestive System Digestive Like Resperation and the circulatory system, the digestive system is simples with the gastro-vascular cavity, where nutrients can be absorbed right through the membrane. Inside the cavity hydrolytic enzymes are released and help digest the food. The next step up was getting rid of the archentron, or mouth, and developing an alimentary canal, which consists of a mouth and an anus.
Food travels down the alimentary canal, into several organs that digest certain organic molecules.
It does this in a chemical and physical way. Chemicals like pepsin and salivary amylase digest chemical, while mastication and the grinding of rocks in the gizzard are examples of physical part.