Why the stomach doesn t digest itself, the human stomach doesn t digest itself, mainly because

Digestion of the stomach is mainly done by gastric juice, which is a liquid similar to hydrochloric acid. Gastric juice is actually very acidic, but the surface of the stomach wall forms a protective film to protect the stomach wall from erosion, which may be the structure of the evolutionary species. But there is a situation where gastric juice can still harm itself, that is, when gastric juice refluxes, it enters the esophagus, you will have a heartburn feeling, commonly known as "nausea", this example should be experienced by most people, this is because there is no protective film in the esophagus.

People with "reflux esophagitis" often feel sick to their stomachs. In addition, if the stomach wall is broken, gastric juice flows into the abdominal cavity, which will also cause you a lot of damage. This is a more popular way to explain, if you ask what the structure of the membrane is, you need to explain the anatomy, tissue composition, etc.

This membrane is simply a simple analogy, "with Durex can be used for contraception", which is almost the same.

The gastric wall can be roughly divided into five layers, from top to bottom, it is the mucosal layer, the mucosal layer, the mucus layer, the muscle layer and the serous layer, the mucosal layer is composed of epithelial cells, mucus cells, parietal cells, master cells, etc., what we call gastric acid is mainly secreted by parietal cells, so it will not corrode the function of stomach and gastric acid.

Stomach acid is made up of hydrochloric acid, which is less corrosive than other acids. Moreover, the concentration of gastric acid in the human body is low, which belongs to dilute acid, and the corrosion of dilute acid on objects is weak;

On the other hand, under normal circumstances, the proteins on the gastric mucosa have a certain resistance to gastric acid and cannot be digested by gastric acid, so they will not cause harm to people!

The stomach has a strong digestive function and relies on hydrochloric acid, pepsin, and mucus in the stomach. Hydrochloric acid is a very corrosive acid that kills bacteria when food enters the stomach. The concentration of hydrochloric acid in the stomach is high, which is enough to dissolve the metal zinc.

Pepsin breaks down proteins in food. Mucus wraps around food, lubricating and protecting the gastric mucosa from food-induced mechanical damage. The hydrochloric acid, pepsin, and mucus in the stomach combine to digest almost any food.

Since the stomach is so digestive, why can't it digest itself? This question was asked more than 100 years ago, and there has never been a complete answer. Some scientists believe that

The stomach cannot digest itself because there is a special substance in the gastric mucosa or gastric juice that resists the action of hydrochloric acid and pepsin. Scientists believe that: first, after the gastric wall secretes hydrochloric acid, hydrochloric acid will not flow backward and will not corrode the gastric wall because it is blocked by the epithelial cells on the mucosal surface.

In the event that the epithelial cells are destroyed, the mucosa secretes mucus, which has a certain buffering effect on hydrochloric acid and also prevents the hydrochloric acid that adheres to the surface of the gastric mucosa from entering the interior. The gastric mucosa also has the ability to "lose the pawn and protect the car", which allows the epithelial cells to constantly metabolize and renew, prevent pepsin from adsorbing on the mucosa, and achieve the purpose of protecting the stomach wall. In addition, the glycoproteins in the mucus, some of which contain a lot of sugar and have a large molecular weight, can inhibit the activity of pepsin.

Secondly, the human gastric mucosa cells are about 500,000 cells per minute, and they can all be renewed within three days, so that the strong regeneration ability can make up for the temporary damage caused by digestive juices to the stomach wall.

So, under normal conditions, the stomach cannot digest itself on its own. If there is too much stomach acid produced in the stomach, or if you take medicine on an empty stomach, the stomach wall is damaged, and the stomach begins to digest itself, and diseases such as gastric ulcers will occur.

Because the stomach is protected by the gastric mucosa, it will digest the food that enters the stomach well, but will not digest the stomach itself.

This is due to the fact that there are certain defenses inside, and there will also be a gastric mucosa to protect the stomach, so it will not digest itself.

Because the stomach secretes a kind of gastric acid, which can digest the food we eat well.

After people eat food, it is quickly digested by gastric juices. Gastric juice is very acidic, but it never digests itself, what is the secret?

In fact, while digesting food, gastric juice also has a certain damaging effect on the stomach wall, that is, causing the death of some cells. However, due to the strong regenerative capacity of the stomach, this damage is only temporary, and the stomach recovers quickly. According to the research data of Professor Deben of the Department of Medicine of the University of Michigan in the United States, every minute of the stomach'The surface is capable of producing about 500,000 new cells.

In other words, it only takes three days to regenerate a new stomach. However, because gastric juice can dissolve the tissue of the stomach within a few hours, it is not enough to fully compensate for the loss caused by the new cells produced. Therefore, you have to have other skills.

The second function of the stomach is that the stomach wall is covered with a thick layer of epithelial cells called the gastric mucosa. It is in direct contact with gastric juices, so that corrosive gastric juices cannot penetrate into the lining of the stomach. We know that if too much acid is produced in the stomach, it can lead to stomach ulcers.

Due to its special protective effect, the gastric mucosa is protected from or only mild acid erosion.

Gastric juice is mainly composed of pepsin and hydrochloric acid. Pepsin is a protein that is a harmless digestive enzyme. However, hydrochloric acid is very corrosive and can easily destroy the tissue cells of the stomach.

Therefore, it is not enough to rely on the regenerative capacity of the stomach and the protective effect of the gastric mucosa. The epithelial cells of the stomach wall are also covered with a thin layer of carbohydrates, the so-called glycosome layer. It can further strengthen the protection of the stomach.

In addition, the lining of the stomach is covered with a layer of fatty substances called lipids. Such substances have a strong inhibitory effect on the hydrogen and chloride ions of hydrochloric acid, which is the third unique activity of the stomach to protect itself.

In recent years, scientists have found that gastric mucosal epithelial cells can continuously synthesize and release endogenous prostaglandins, which have a significant protective effect on the gastrointestinal mucosa. In addition, it has been shown that the gastrointestinal tract is the largest endocrine organ in the human body and secretes new hormones (all peptides).

Because the stomach secretes liquid, it can play a lot of roles, and will produce some special substances that can break down the food in the stomach and will not digest itself.

Because there will be some stomach acid in the stomach, you can get a good digestion at this time, don't worry about such things, everyone will be like this in the house.

It's because the stomach has a protective mucous membrane, so it definitely won't digest itself, and can only digest some food.

Because the stomach has the ability to discriminate, they don't eat themselves.

It is because the gastric mucosa has a good protective effect, and the gastric mucosa will only digest other items, so it will not digest itself.

Because there is a gastric mucosa in the stomach, and the gastric mucosa can effectively resist the action of acid and some digestive enzymes, it will not corrode the stomach.

The main reason is that the stomach has a certain degree of corrosion resistance, and the stomach acid is secreted by itself, so you don't have to worry about the impact.

Because our organs have a lot of cells, and there are some gastric mucosa in our stomach, the viscosity of this gastric mucosa is very large, and it can protect the stomach, so we will not digest ourselves.

Many people will have such a question, gastric juice can digest meat and other proteins, why not digest the stomach itself? (The stomach is also mostly made up of protein.) ）

Gastric juice does digest the stomach, but why is the stomach not digested? This is because of the multifaceted protective effect:

One is that the stomach builds a protective film for itself. The stomach can not only secrete "gastric acid" and "pepsinogen" to digest food, but also secrete mucus and bicarbonate, the latter forming a thick protective film that isolates the gastric mucosa from gastric juice, so that it is difficult for gastric juice to directly contact the gastric mucosa, so it only digests food, not the stomach itself. However, if there is a hole in the protective film, it can lead to the erosion of local gastric tissue, and in severe cases, it can form ulcers and other stomach diseases.

Second, there is a lipoprotein membrane on the surface cells of the gastric mucosa to isolate gastric juice to protect the gastric mucosa.

The third is that the gastric parietal cells are constantly renewed, and the old cells are constantly shedding from the surface and replaced by new cells. About 500,000 cells are shed in the stomach every minute, and the gastric mucosal layer is fully renewed every 3 days. Therefore, even if a small amount of stomach acid penetrates through the upper two layers of protective film and causes a certain degree of damage to the lining of the stomach, it can be completely repaired within a few days or hours.

The stomach has such a strong self-protection function (and this is only a part of it), why do we still have stomach problems?

Although the stomach has a strong protective mechanism and a strong repair ability, it is still very fragile, drinking a lot of wine, overeating, eating barbecue smoked and other foods will cause damage to the stomach, and the number of times of destruction is too much, and the stomach itself can not be repaired, and it forms a stomach disease!

If you already have symptoms, you should be very careful, because the stomach has already sent an alarm signal. In addition to developing good lifestyle habits, it is best to have a gastrointestinal endoscopy to rule out bowel cancer and stomach cancer, and the incidence of these two types of cancer has risen to the first.

Two or three.