A digestive system is a group of organs working together to break down food into tiny molecules. Digestion of food is important so that we can obtain energy from our food.
There are three ways the digestive system supports our body
Digestion - It is the process of breaking down food into smaller particles (i.e. nutrients) that can be absorbed by our bodies. There are two types of digestion:
Absorption - After food is broken down into nutrients molecules, the nutrients can be moved through the blood. This process is called absorption. Nutrients travel through the bloodstream to feed all our cells.
Elimination - Some substances in food can’t be broken down into nutrients. They remain behind after digestion has occurred. Any food that can’t be digested is passed out of the body as solid waste. This process is called elimination.
The following image shows the major organs of the digestive system.
The digestive system begins in your mouth. When you do eat, the saliva breaks down the chemicals in the food a bit, which helps make the food mushy and easy to swallow. Your tongue helps out, pushing the food around while you chew with your teeth. When you're ready to swallow, the tongue pushes the mushed-up food toward the back of your throat and into the opening of your esophagus, the second part of the digestive tract.
The esophagus is like a stretchy pipe. It moves food from the back of your throat to your stomach. Also, at the back of your throat is your windpipe, which allows air to come in and out of your body. When you swallow, a special flap called the epiglottis flops down over the opening of your windpipe to make sure the food enters the esophagus and not the windpipe.
Once food has entered the esophagus, the muscles in the walls of the esophagus move in a wavy way to slowly squeeze the food through the esophagus. This takes about 2 or 3 seconds.
Your stomach is attached to the end of the esophagus. It is a stretchy sack-shaped organ. It performs three important functions:
The stomach is like a mixer, churning and mashing together all the small balls of food that came down the esophagus into smaller and smaller pieces. It does this with the help of the strong muscles in the walls of the stomach and gastric juices that also come from the stomach’s walls. In addition to breaking down food, gastric juices also help kill bacteria that might be in the eaten food.
Next, the smaller pieces go into the small intestine. The small intestine is a long tube that’s about 1.5 – 2 inches around and is packed beneath the stomach. An adult’s small intestine is about 22 feet long (6.7 meters). Most chemical digestion and almost all nutrient absorption take place in the small intestine.
The small intestine is made up of three parts:
The small intestine help extracts nutrients with the help of juices secreted from three other organs, namely, pancreas, liver and gall bladder.
Your food may spend as long as 4 hours in the small intestine and will become a very thin, watery mixture.
These nutrients go to the liver and the leftover waste — parts of the food that your body can't use — goes on to the large intestine.
The nutrient-rich blood comes directly to the liver for processing. The liver filters out harmful substances or wastes, turning some of the waste into more bile.
The last stage is the large intestine. Any food that the body doesn't need or can't use is sent to the large intestine and later leaves the body as waste. Before it goes, it passes through the part of the large intestine called the colon, which is where the body gets its last chance to absorb the water and some minerals into the blood. As the water leaves the waste product, what's left gets harder and harder as it keeps moving along, until it becomes a solid (called poop).
The large intestine pushes the poop into the rectum, the very last stop on the digestive tract. The solid waste stays here until you are ready to go to the bathroom. When you go to the bathroom, you are getting rid of this solid waste by pushing it through the anus.
