KEY CONCEPT The digestive system breaks down food into simpler molecules.

Several digestive organs work together to break down food. The digestive system breaks down food into energy cells can use. After digestion is complete, nutrients are absorbed and transported to all cells. Undigested materials are eliminated as liquid and solid wastes. mouth esophagus liver gallbladder large intestine small intestine rectum/anus

Digestion begins in the mouth and continues in the stomach. Mechanical and chemical digestion break down food. Peristalsis moves food through the organs. esophagus muscles contract muscles relax food stomach

Digestion of carbohydrates begins in the mouth. Digestion of proteins occurs in the stomach. Digestion of fats and sugars occur in the small intestine.

Digestion is completed in part of the small intestine. Most digestion takes place in the duodenum. The pancreas, liver, and gallbladder aid in digestion. pancreas helps digest fat and protein bile from the liver/gallbladder helps digest fats liver stomach bile chyme bile enzymes gallbladder pancreas duodenum