Main Organs

The main organs that make up the digestive system (in order of their function) are the mouth, esophagus, stomach, small intestine, large intestine, rectum and anus. Helping them along the way are the pancreas, gall bladder and liver. 

Functions

Your body takes in and breaks down food in two parts: mechanical digestion and chemical digestion. 

Mechanical Digestion - To begin the process of digestion, food and water enters the mouth. Then, the food is chewed with your teeth to break it into small pieces. This process of breaking down the food into smaller pieces is called mechanical digestion.

Chemical Digestion -Next, the mushed up food travels down your esophagus to your stomach. In the stomach, the body releases enzymes (specialized chemicals) that melt down the small pieces of food into nutrients. This is called chemical digestion.

Once the food is completely broken down, now it's time for your body to absorb important nutrients and water. 

Absorbing Nutrients and Water - Then, nutrients move from your stomach to your small intestine. The nutrients your body needs are absorbed from your small intestine into your circulatory system. The circulatory system carries nutrients to your cells where it is changed into energy. 

The extra nutrients and water are moved into the large intestine where water is absorbed into your circulatory system. The circulatory system moves the water to different parts of the body that need it.

So how do all those nutrients actually get to your cells? The digestive system works very closely with the circulatory system! Once the food is broken down into small pieces, the circulatory system, specifically capillaries, line the outside of your intestines and they pick up important nutrients and water and transports them to each cell in your body!

Digesting Food

Digesting food requires teamwork between the digestive system and several other organ systems, including the nervous, cardiovascular, and muscular systems. When you eat a meal, the organs of the digestive system need more blood to perform their digestive functions. Food entering the digestive systems causes nerve impulses to be sent to the brain; in response, the brain sends messages to the cardiovascular system to increase heart rate and dilate blood vessels in the digestive organs. Food passes through the organs of the digestive tract by rhythmic contractions of smooth muscles in the walls of the organs, so the muscular system is also needed for digestion. After food is digested, nutrients from the food are absorbed into the blood of the vessels lining the small intestine. Any remaining food waste is excreted through the large intestine.