In a few minutes you're thinking about the capital of Oregon or your science fair project. You've completely forgotten about that pizza lunch you just ate. But it's still in your stomach — sort of like a science experiment that happens all the time! Your digestive say: dye-JES-tiv system started working even before you took the first bite of your pizza. And the digestive system will be busy at work on your chewed-up lunch for the next few hours — or sometimes days, depending upon what you've eaten.
This process, called digestion , allows your body to get the nutrients and energy it needs from the food you eat. So let's find out what's happening to that pizza, orange, and milk. Even before you eat, when you smell a tasty food, see it, or think about it, digestion begins. Saliva say: suh-LYE-vuh , or spit , begins to form 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 a tiny bit of mushed-up food called a bolus say: BO-luss toward the back of your throat and into the opening of your esophagus, the second part of the digestive tract.
The esophagus say: ih-SOF-eh-guss is like a stretchy pipe that's about 10 inches 25 centimeters long. It moves food from the back of your throat to your stomach.
But 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 small ball of mushed-up food or liquids, a special flap called the epiglottis say: ep-ih-GLOT-iss flops down over the opening of your windpipe to make sure the food enters the esophagus and not the windpipe. If you've ever drunk something too fast, started to cough, and heard someone say that your drink "went down the wrong way," the person meant that it went down your windpipe by mistake.
This happens when the epiglottis doesn't have enough time to flop down, and you cough involuntarily without thinking about it to clear your windpipe. Once food has entered the esophagus, it doesn't just drop right into your stomach. Instead, 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, which is attached to the end of the esophagus, is a stretchy sack shaped like the letter J. It has three important jobs:.
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. When someone eats, the teeth chew food into very small pieces.
Glands in the cheeks and under the tongue produce saliva that coats the food, making it easier to be chewed and swallowed. Saliva also contains enzymes that start to digest the carbohydrates in food. The oesophagus is the muscular tube that carries food from the mouth to the stomach after it is swallowed. A ring of muscle at the end of the oesophagus relaxes to let food into the stomach and contracts to prevent stomach contents from escaping back up the oesophagus.
The stomach wall produces gastric juice hydrochloric acid and enzymes that digests proteins. The stomach acts like a concrete mixer, churning and mixing food with gastric juice to form chyme — a thick, soupy liquid.
Bile from the gallbladder and enzymes in digestive juices from the pancreas empty into the upper section of the small intestine and help to break down protein into amino acids and fat into fatty acids.
These smaller particles, along with sugars , vitamins and minerals , are absorbed into the bloodstream through the wall of the small intestine. It is called small because it is about 3. Most of the chemical digestion of proteins, fats and carbohydrates is completed in the small intestine.
The lining of the large intestine absorbs water, mineral salts and vitamins. Undigested fibre is mixed with mucus and bacteria — which partly break down the fibre — to nourish the cells of the large intestine wall and so help keep the large intestine healthy. Faeces are formed and stored in the last part of the large intestine the rectum before being passed out of the body through the anus.
Gastro-oesophageal reflux GORD occurs when acidic stomach contents move from the stomach back up the oesophagus. It causes a burning sensation in the chest or throat. Diverticulitis is caused by inflammation or infection of abnormal pouches in the lower part of the large intestine. It can cause mild or severe pain on the lower left-hand side of the abdomen.
Stomach ulcers are commonly caused by the bacterium Helicobacter pylori that can live in the stomach of about 4 in 10 Australians. They can cause long-term, low-level inflammation of the stomach lining in some people. It is not well understood why they cause stomach ulcers in some people and not in others. Haemorrhoids are itchy or painful lumps that occur in and around the anus.
The lumps contain swollen blood vessels. Haemorrhoids can cause bleeding when you go to the toilet do a poo — you might notice bright red blood on the toilet paper or in the toilet. If you find blood on the toilet paper or in the toilet, always seek medical advice. Learn more here about the development and quality assurance of healthdirect content.
Read more on Better Health Channel website. Stomach cancers also called upper gastrointestinal UGI cancers happen in the organs that are found in the upper section of the digestive system. The UGI organs of the digestive system how we eat and process food include:. Lower gastrointestinal cancer also called bowel or colorectal cancer happens in the large intestine of the digestive system.
The digestive system how we eat and process food has two intestines that travel from the stomach to the anus. Stomach cancers happen in the organs that are found in the upper section of the digestive system.
The digestive system is a series of hollow organs such as the stomach and small intestine. Around half of cases of anal fissures heal by themselves with proper self-care and avoidance of constipation. Anyone of any age can be struck by appendicitis, but it seems to be more common during childhood and adolescence. Content on this website is provided for information purposes only.
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The information and materials contained on this website are not intended to constitute a comprehensive guide concerning all aspects of the therapy, product or treatment described on the website. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions and to ascertain whether the particular therapy, service, product or treatment described on the website is suitable in their circumstances.
The State of Victoria and the Department of Health shall not bear any liability for reliance by any user on the materials contained on this website. Skip to main content. 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 Things to remember. 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.
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