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Digestive system explained. Actions for this page Listen Print. Summary Read the full fact sheet. On this page. The mouth and oesophagus The stomach The small intestine Pancreas Liver The large intestine Common problems in the digestive system Where to get help. The mouth and oesophagus Digestion begins in the mouth.

The stomach The food passes through a sphincter, or small muscle ring, into the stomach. The small intestine Once in the duodenum, the food is mixed with more digestive enzymes from the pancreas and bile from the liver. Pancreas The pancreas is one of the largest glands in the human body.

Liver The liver has a number of different roles in the body, including: breaking down fats, using bile stored in the gall bladder processing proteins and carbohydrates filtering and processing impurities, drugs and toxins generation of glucose for short-term energy needs from other compounds like lactate and amino acids.

The large intestine Once all the nutrients have been absorbed, the waste is moved into the large intestine, or bowel. Common problems in the digestive system Some common problems include: colitis — inflammation of the bowel diverticulitis — inflammation of pouches lining the small intestine gastroenteritis — an infection that causes vomiting and diarrhoea heartburn — when the contents of the stomach back up into the oesophagus ulcer — a hole in the mucous membrane lining the stomach or duodenum.

Where to get help Your doctor. Give feedback about this page. Was this page helpful? The liver, pancreas, and gallbladder are the solid organs of the digestive system.

The small intestine has three parts. The first part is called the duodenum. The jejunum is in the middle and the ileum is at the end. The large intestine includes the appendix , cecum, colon , and rectum.

The appendix is a finger-shaped pouch attached to the cecum. The cecum is the first part of the large intestine.

The colon is next. The rectum is the end of the large intestine. Bacteria in your GI tract, also called gut flora or microbiome, help with digestion.

Parts of your nervous and circulatory systems also help. Working together, nerves, hormones , bacteria, blood, and the organs of your digestive system digest the foods and liquids you eat or drink each day. Digestion is important because your body needs nutrients from food and drink to work properly and stay healthy.

Proteins , fats , carbohydrates , vitamins , minerals , and water are nutrients. Your digestive system breaks nutrients into parts small enough for your body to absorb and use for energy, growth, and cell repair. MyPlate offers ideas and tips to help you meet your individual health needs.

Each part of your digestive system helps to move food and liquid through your GI tract, break food and liquid into smaller parts, or both. Once foods are broken into small enough parts, your body can absorb and move the nutrients to where they are needed.

Your large intestine absorbs water, and the waste products of digestion become stool. Nerves and hormones help control the digestive process. Food moves through your GI tract by a process called peristalsis.

The large, hollow organs of your GI tract contain a layer of muscle that enables their walls to move. The movement pushes food and liquid through your GI tract and mixes the contents within each organ.

The muscle behind the food contracts and squeezes the food forward, while the muscle in front of the food relaxes to allow the food to move. Food starts to move through your GI tract when you eat. When you swallow, your tongue pushes the food into your throat.

A small flap of tissue, called the epiglottis, folds over your windpipe to prevent choking and the food passes into your esophagus. Once you begin swallowing, the process becomes automatic. Your brain signals the muscles of the esophagus and peristalsis begins.

Lower esophageal sphincter. When food reaches the end of your esophagus, a ringlike muscle—called the lower esophageal sphincter —relaxes and lets food pass into your stomach. After food enters your stomach, the stomach muscles mix the food and liquid with digestive juices.

The stomach slowly empties its contents, called chyme , into your small intestine. Small intestine. The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine, and push the mixture forward for further digestion.

The walls of the small intestine absorb water and the digested nutrients into your bloodstream. As peristalsis continues, the waste products of the digestive process move into the large intestine.

Large intestine. Waste products from the digestive process include undigested parts of food, fluid, and older cells from the lining of your GI tract. The large intestine absorbs water and changes the waste from liquid into stool.

Peristalsis helps move the stool into your rectum. The lower end of your large intestine, the rectum, stores stool until it pushes stool out of your anus during a bowel movement. Watch this video to see how food moves through your GI tract.

As food moves through your GI tract, your digestive organs break the food into smaller parts using:. The digestive process starts in your mouth when you chew. Your salivary glands make saliva , a digestive juice, which moistens food so it moves more easily through your esophagus into your stomach.

Saliva also has an enzyme that begins to break down starches in your food. After you swallow, peristalsis pushes the food down your esophagus into your stomach.

How much water you need per day depends on many factors like your size, activity level, and health. In general, adults need cups of water per day. Good choices are: water, green tea, black coffee, fat-free milk, fresh-squeezed juice.

Regular exercise helps food move through your digestive system faster, reducing the risk of nausea, bloating, constipation. Regular exercise can also improve the symptoms of constipation and inflammatory bowel disease. Good choices are: taking a walk after meals or 30 minutes of moderate to vigorous exercise daily.

Maintaining a healthy weight reduces your chances of developing GERD, gallstones, some digestive cancers, and more. Following suggestions for a healthy diet and regular exercise can help you maintain a healthy weight. You know smoking is bad for your lungs, but you might be surprised to find that it’s also bad for your digestive system.

Smoking has been found to significantly increase your risk of developing acid reflux, and quitting has been shown to improve symptoms. Research has also found a link between smoking and stomach ulcers and an increased need for surgery for gastrointestinal cancers and ulcerative colitis.

Good choices are: talk to your doctor about help for quitting, or visit Smokefree. gov for information and help. Lack of sleep affects every body system, including the digestive system. Sleep deprivation may lead to inflammation in the bowel, which can cause gastrointestinal symptoms.

Long-term stress negatively affects your overall health and is linked to diarrhea, constipation, IBS, and ulcers.