Production line digestion Show all answers
If the stomach rumbles, we know immediately: our body needs nourishment. Because every single cell in our organism needs energy so that it can function properly. And it gets this from the air that we breathe, the water we drink and the food that we eat. The smaller our cells are, the smaller our breakfast, lunch and evening meal must be decomposed by our body so that the nutrients can reach them at all. For this reason our digestive system is similar to a big factory with many departments and employees who work hand in hand at a conveyor belt so that each body cell gets its supplies.
Stage 1: Delivery Zone Mouth
bite a piece off, nose and eyes have usually already sent a text message to the brain: “Watch out, everyone to the saliva pumps! Food is on the way!” The saliva glands spring into action, making the mouth literally “water”. Then the gates open and the first delivery is taken. The sawing and grinding begins. The teeth quickly make small pieces, enzymes in the saliva transform starch into sugar. They also sort out many harmful substances such as heavy metals so that they can later be disposed of by the colon. While the tongue is rolling the food backwards and forwards, thousands of taste buds record the quality of the “goods” and pass their impressions on to the brain. Delicious or horrid? Spicy or mild? Now, taste, consistency, seasoning or aroma of the food determine whether we continue chewing or spitting it out. But not only for our factory’s own quality control is it important to chew every bite for a long time. Plant and meat fibres are metabolised better, the digestive organs work more effectively and the feeling of fullness is perceived more quickly - - important for all those who wish to lose weight.
Stage 2: Conveyor Belt Oesophagus
it is slippery enough thanks to the saliva, we swallow it so that it arrives in the oesophagus – if we don’t let it find the wrong entrance at the side, i.e. the windpipe, which makes us cough. The ring-shaped muscles around the oesophagus contract continually, the food pulp gradually slides downwards and finally lands in the stomach.
Stage 3: Chemical Department Stomach
ground even smaller. There is nothing dainty about this procedure. Stomach juices with achlorhydria splits chemical compounds in the food, even dissolves metals and kills harmful bacteria. Further tools in this work hall are, among others, enzymes that decompose proteins and fats. Plenty of food expands the muscular walls of the stomach which reports when it is full enough: a feeling of fullness is registered. People who permanently eat too much, expand the stomach walls beyond their normal measure – and thus feel full later. But, despite the rough treatment here, our food is still not digested properly at this stage. For this reason, it must be passed on into the small intestine in small portions.
Stage 4: Digestive Centre Small Intestine
of 6 to 8 metres. Here, the main digestion process takes place. The first section is twelve breadths of the finger long and leads to the bile duct: the duodenum. Again it reduces the high acidic content of the food pulp. While the liver next-door incessantly produces bile acid and stores it in the gall bladder, this is specifically added to the food pulp via the bile duct all and dissolves fat at this stage.
Here the pancreas also opens into the duodenum. If forms a secretion that contains nearly all the enzymes – and the well-known substance insulin (so-called because it is formed by island cells in the pancreas) – which are essential for decomposition. Insulin together with many hormones has its function in the regulation of the blood sugar content. A lack of insulin leads to diabetes mellitus.
Our small intestine has a surface of about 100 square metres if one would flatten out all the folds and villi, and then measure the length. It needs all this space to be able to absorb as many nutrients as possible while the food pulp is passing through it. Again it is the enzymes that dissolve the tiniest components so that they can be absorbed into the bloodstream via the mucous membrane of the small intestine. Proteins are decomposed into amino-acids, carbohydrates i. a. into glucose – therefore sugar compounds – and split fats into fatty acids and glycerine. Nutrients including vitamins and minerals are dissolved and therefore transportable.
Stage 5: Final Processing Large Intestine or Colon
or the salami sandwich. Most of the remaining water is drawn out of the digested pulp. However, because there are still some useful minerals hidden in it, the large intestine or colon is rich in bacteria that have specialised in processing the remaining substances that are difficult to digest.
Thus the nutrients are brought via the whole intestine into the bloodstream and lymph system right to the last body cell. On the other hand, the digestive system also prevent harmful substances getting through – and with its many bacteria cultures provides a barrier and represents an important component of our immune system. Amongst other things, roughage or dietary fibres speeds up the passage through the bowels and therefore reduces the contact time of the harmful parts of our nutrition with the mucous tissue of the bowels, which in turn reduces the risk of bowel cancer. The indigestible, thickened remains of our food finally pass into the rectum and are disposed of via the anus.
However, before the last little particle of unused breakfast is rinsed away for ever, it is important to emphasise once again how important not only roughage, but all the various nutrients in our food are for our whole digestive system. After all, what we do not give our body of these important substances in the form of a top-quality and balanced diet, it cannot find for itself – and our cells can call it a day!