Waves of muscle contractions called peristalsis (per-uh-STALL-sus) force food down through the esophagus to the stomach. A soft flap of tissue called the epiglottis (ep-ih-GLAH-tus) closes over the windpipe when we swallow to prevent choking.įrom the throat, food travels down a muscular tube in the chest called the esophagus (ih-SAH-fuh-gus). The pharynx is a passageway for food and air. Swallowing, done by muscle movements in the tongue and mouth, moves the food into the throat, or pharynx (FAIR-inks). A digestive enzyme in saliva called amylase (AH-meh-lace) starts to break down some of the carbohydrates (starches and sugars) in the food even before it leaves the mouth. When we see, smell, taste, or even imagine a tasty meal, our salivary glands in front of the ear, under the tongue, and near the lower jaw begin making saliva (spit).Īs the teeth tear and chop the food, spit moistens it for easy swallowing. An adult's digestive tract is about 30 feet (about 9 meters) long.ĭigestion begins in the mouth, well before food reaches the stomach. The alimentary canal is the long tube of organs - including the esophagus, stomach, and intestines - that runs from the mouth to the anus. The digestive system is made up of the alimentary canal (also called the digestive tract) and other organs, such as the liver and pancreas. The waste parts of food that the body can't use are what leave the body as feces. Fats break down into into fatty acids and glycerol.Starches break down into simple sugars.Protein must be broken down into amino acids.exits the body as feces (poop) through the anusĪlong the way, food is broken down into tiny molecules so that the body can absorb nutrients it needs:.Just by smelling that homemade apple pie or thinking about how delicious that ripe tomato is going to be, you start salivating - and the digestive process begins in preparation for that first bite.Īlmost all animals have a tube-type digestive system in which food: The first step in the digestive process happens before we even taste food. But before food can do that, it must be digested into small pieces the body can absorb and use. Food is our fuel, and its nutrients give our bodies' cells the energy and substances they need to work.