Digestive system

by. jessica lee

overall functions

Digestive system's main function is to convert foods into nutrients and energy we need to survive. It also moves the unused waste material out of the body.

organs/individual roles/specialized cells

Mouth, edophagus, stomach, small intestine, pancreas, liver, gall bladder, large intestine, rectum, anus all have each different roles in the digestive system to function. The mouth starts chewing and breaks the food into pieces that are more easily digested. The saliva inside the mouth mixes with foods to begin the process of breaking it down into a form your body can absorb and use. Esophagus is located in your throat and it receives food from your mouth when you swallow. By means of a series of muscular contractions called peristalsis, the esophagus delivers food to your stomach.

The stomach holds the food while it is being mixed with enzymes that continue the process of breaking down food into a usable form. Cells in the lining of the stomach secrete a strong acid and powerful enzymes that starts the breakdown process. When the contents of the stomach are broken down, they are released into the small intestine.

The small intestine is a muscular tube made up of three segments: duodenum, jejunum, and ileum. The tube breaks down the food using enzymes released by the pancreas and bile from the liver. The enzymes from pancreas break down protein, fats, and carbohydrates. Liver process the nutrients absorbed from the small intestine and digest fats. Peristalsis moves the food through and mixes it with digestive secretions from the pancreas and liver. The gallbladder stores and concentrates bile, and then releases it into the duodenum to help absorb and digest fats. The duodenum is largely responsible for the continuous breaking-down process, while the jejunum and ileum are mainly responsible for absorption of nutrients into the bloodstream. Once all the nutrients are absorbed, the leftover moves on to the large intestine.

Large intestine process waste so that emptying the bowels is easy and convenient. When the intestine is full, it empties its contents into the rectum to begin the process of elimination. The rectum let the person know that there is waste need to be excreted and holds om the waste until evacuation happens. Anus is the last part of the digestive system and it lets you know whether the contents are liquid, gas, or solid. The anus is surrounded by sphincter muscles that are important in allowing control of stool. The pelvic floor muscle creates an angle between the rectum and the anus that stops stool from coming out when it is not supposed to. When the rectum is full, the muscle surrounding anus will open and evacuate the waste.


Digestive and excretory systems eliminate metabolic wastes.