Human body is a complex system. Plenty of works run nonstop inside the human body. Digestive system is a crucial part of human body. Many people get confused when it comes to understanding the digestive system. Here we are going to take a look at digestive system and how does it work. After taking the food it breaks down. There are various chemicals and acids secrete in our body. The food changes the form and gets absorbed into the blood stream then. It happens because of the chemical reactions. The salt, sugar, glucose and water in the food remain unchanged. Other contents like fat, protein and starches must be broken. There are enzymes inside our digestive system that helps a lot to digest the food properly. The digestive system starts from our tongue. We chew the food first and it gets mixed up with saliva. There are enzymes in the saliva that breaks the food in small molecules. You need to chew the food well so that it can comfortably pass through the esophagus. Esophagus ends up in the stomach. The esophagus rings open in one way and that is why the food or the acids do not come back to the esophagus. Sometimes the food can be regurgitated if the ring is not close properly. This is known as a common digestive problem. Heartburn and indigestion can also happen in this case. Those who are suffering from hiatal hernia often suffer from these troubles. Inside the stomach the food is churned well by the muscular walls of the stomach. The stomach walls also produce gastric acid and pepsin. There are mucus producing cells too and it prevents the enzymes from digesting the tissues inside stomach. When these processes fail the person suffers from ulcer.