La danza della digestione: cosa succede nello stomaco? Ecosalute

The dance of digestion: what happens in the stomach?

In the collective imagination, the stomach is a strong organ , which dissolves, digests and mixes. A courageous person has no hair on his stomach, or someone who is not impressed has a strong stomach. In reality this organ is in a delicate balance regulated by very fine chemical, physical and hormonal mechanisms . These regulate each other and control the entire digestive process .

The stomach has a very particular structure and was perfectly designed by Mother Nature to fulfill its multiple tasks. Starting from the inside, there is a layer of mucosa in which the glands that secrete gastric juices are present and a layer of submucosa to surround it to increase insulation and avoid the risk of those highly acidic juices self-digesting the organ. The most unique part is the triple layer of muscles in circular, oblique and longitudinal directions, which allow peristaltic movements, those that mix food inside the stomach. We then find the serosa enveloping the organ.

By pointing a microscope at the mucosal layer, we can see the parietal cells that secrete hydrochloric acid when receptors in the mouth send the signal for food to arrive. This is a critical moment of digestion : hydrochloric acid not only begins to dissolve the bolus (as the food is called once it is swallowed), but also regulates the activation of pepsin , a proteolytic enzyme that begins the digestion of proteins .

It also acts as a defense against pathogens , which are neutralized thanks to its acidity. Furthermore, the level of acidity of the bolus, which will now be called chyme, also determines the release of other digestive enzymes from the pancreas and bile from the gallbladder. Stomach epithelial cells secrete bicarbonate to buffer the highly acidic pH of hydrochloric acid, while mucosal cells secrete mucus to protect the stomach wall from damage that gastric juices and digestive enzymes might cause. Finally, the Intrinsic Factor is also released from the stomach, necessary for the absorption of vitamin B12 .

We can therefore appreciate this duality of the stomach, where on the one hand we have the secretion of a very powerful acid and a unique and equally strong musculature, on the other hand there are delicate mechanisms that regulate each other and are influenced by multiple factors, both internal and external. external.

Now that we have a drawing of what the stomach looks like, let's see what happens when the balance is disturbed.

The most common gastric problem is certainly reflux , also known as gastroesophageal reflux or GORD . There may be genetic causes and greater individual sensitivity , but more commonly the origin is to be found in many aspects of lifestyle , some controllable, others less so. Another aspect to consider is that this problem is more widespread in the over 50s , particularly in men . In fact, after the age of fifty the production of hydrochloric acid decreases: therefore the ideal situation ( the ideal pH ) is no longer created for which all the other digestive mechanisms are activated, the food is digested with difficulty and slowly and remains in the stomach for too long time. You therefore perceive heaviness and consequently also reflux given by the chyme, mixed with acid, enzymes and bicarbonate, which is not properly discharged from the pylorus and which partially escapes from the cardia.

The burning sensation that is felt in the pit of the stomach can reach up to the throat, in fact many times reflux is not diagnosed promptly and is mistaken for a sore throat. These symptoms usually appear after meals , while if the burning sensation is always present then the problem could be another (gastritis, hyperchloridia, etc...). Even the powerful muscles of the stomach, if not stimulated by pH and other factors, slow down and no longer mix the chyme properly, making digestion even more difficult.

The factors that aggravate reflux are of nutritional and postural origin : hot and spicy foods, coffee, alcohol, dairy products and vinegar, going to bed just after meals, eating quickly and drinking lots of water while eating. Adopting some changes definitely helps to reduce the symptoms, perpetrating bad habits, unfortunately the situation can only worsen, up to the point of taking drugs which however do not treat the pathology but only the symptoms.

The stomach, our organ of courage and strength , must therefore be treated with respect and delicacy . The balances that regulate it start even before the food reaches our mouth, when we smell a good smell or even just with the visual stimulus of foods that tantalize us. They then end when the chyle (this is the name of the food when it is in the intestine) reaches the colon, as the secretions and intestinal movements also start and end thanks to signals coming from the stomach. There is a dance of acids, bases , hormones, ions and mucus that participates in this delicate and very important moment, because everyone likes to eat well and happily , and it is important that the stomach is well and in harmony.