"Our digestive system is a complex collection of organs, perfectly engineered!"
Your digestive system plays a vital role in supporting your natural defences, preventing digestive problems and contributing to the health of the whole body. It’s a complex collection of organs that work together to make sure the nutrients, vitamins and minerals essential for overall health can be used and absorbed in the body. And each section of our gut is perfectly engineered for its own 'food processing' role.
Your body begins breaking down food here. Food is chewed and mixed with saliva, which contains enzymes to break down the larger molecules of food.
The Small Intestine
The small intestine is actually 24 feet of elaborately folded tubing. If stretched out flat, it would be around the size of a tennis court. As food moves along this tube, enzymes released by the pancreas and the intestine itself break it down into smaller molecules of carbohydrate, protein and fat. These can then be absorbed through the intestinal wall into the bloodstream. Tiny folds on its inner surface (called villi and micro-villi) create a vast area through which these molecules can be absorbed.
The pancreas is not strictly part of the digestive system. But it plays an essential part in digestion. Sitting just behind the stomach, this gland secretes an alkaline juice that neutralises stomach acid and contains enzymes that help to break down food within the small intestine.
Food is pushed down this tube by powerful muscular contractions known as peristalsis. These rhythmic contractions begin at the top of the oesophagus and travel through the entire gut, keeping your food moving along.
Food can remain in the stomach for up to four hours. During this time, it is mixed with a number of gastric juices, including enzymes (which break down proteins, starches and liquids) and acid (which kills most of the bacteria present). The resulting thick liquid passes, little by little, into the small intestine.
The Large Intestine
Although there are a number of bacteria in the small intestine, it is in the large intestine (also known as the colon) that the majority of gut bacteria are found. These trillions of resident bacteria break down any undigested food coming from the small intestine. Some gut bacteria may also synthesise vitamins. Faeces are compacted, ready to be excreted from the body. The large intestine is also where water is absorbed into the bloodstream.
The largest gland in the human body, the liver receives nutrients from the gut via the blood and metabolises them (breaks them down) in a variety of ways. The liver also makes bile, which helps to digest fat within the small intestine. Bile is secreted down a tube called the bile duct, into the gall bladder.
The Gall Bladder
This concentrates bile and squeezes it into the small intestine where it emulsifies and helps to break down fat.