The Digestive System


Digestion is a process in which your body converts your food into simpler forms which can be used to
supply energy and building materials for growth. Food enters your body through your mouth. Your tongue
moves the food around while your teeth chew it up. The tongue also aids in the process of swallowing the
food. The salivary glands add saliva to the mouth. The saliva contains an enzyme call Salivary Amylase
which changes the starches in the food to sugars. These sugars give us energy. It also moistens the food.
The food then goes through the esophagus and then to the stomach. Muscular contractions, also called
peristalsis, cause the food to move through the digestive system. Then the food goes to your stomach. The
stomach contains Hydrochloric acid and other digestive juices that causes the breakdown of complex
proteins into simpler substances that can be used as building blocks for our body cells. Most fats are also
broken down. To break down, the food is squeez!
ed. Food remains here for about 4 hours. When the food leaves the stomach, it goes into the duodenum or
the first part of the small intestine. The small intestine is about 9 meters long. Digestion of the food is
complete when digestive juices from the pancreas and the liver are add into the food. These help to change
the food into liquid. These help to change the complex sugars, proteins and fats into materials that our
body cells can use. The broken down food is now absorbed by tiny vessels of the projections called villi
that line the small intestine. Once in bloodstream, the food is carted to all parts of the body. Some of the
food is not digested are pushed by muscular movements of the small intestine into the large intestine. The
large intestine is made of three parts called the ascending, transverse, and descending colon and the
appendix. The unused food is stored in the lower part, the anus, until it is eliminated by a bowel movement
through the anus. In the!
large intestine water is removed from the unused food. The human body needs food a)for growth and
repair of the body tissues. b) to provide us with the energy we need. c) proper functioning of the body.
Some of the main classes of foods are carbohydrates, fats, proteins, vitamins, mineral salts, and water.
Different parts of your body do different work so you can live. These parts are called organs. Some of the
organs in your digestive system chew food and squeeze it to help to break it down so your body can use it.
Some of the organs in your digestive system make something. They are called glands. They put digestive
juices into food to help change it. Your body breaks down, or digests food so that cells can use it. Your
body has enzymes that help digest food. Diastase breaks down starch and starts to change it into sugars so
that your body can use it.