Biology The Digestive System

The Digestive System

• Animals need to absorb nutrients to obtain energy. The process of breaking down food to obtain nutrients is called digestion. Animals are adapted to ingest and digest food in different ways, but many invertebrates and all vertebrate animals have a specialized digestive system to facilitate the processes involved.

• Structurally simple animals like sponges, flatworms and hydras have a simple digestive system with a single opening. Other animals have a complete digestive system running from the mouth to the anus.

• This Lesson looks at the general structure of an animal digestive system, We’ll go on to follow the path of food through the human digestive system, examining the roles of the different organs involved, and seeing how fats, carbohydrates and proteins in foods are broken down by enzymes and other chemicals in the digestive tract.

• We’ll also examine the control of the digestive system, which involves both nervous and hormonal processes.