Secretion of gastric juice occurs through the work of the gastric mucosa. It is a colorless, odorless liquid with small lumps of mucus. Any deviations from this norm, for example a change in color and density, indicate the presence of problems with the gastrointestinal tract. The composition of the gastric juice is complex, because it is produced by various cells of the gastric mucosa. Its main component is hydrochloric acid, which, in turn, has a concentrated composition.
The composition of the gastric juice
In addition to hydrochloric acid, the following components are included in gastric juice
- Bicarbonates (they neutralize the destructive effect of hydrochloric acid on the walls of the stomach).
- Pepsinogen, converted to pepsin (the latter is involved in the breakdown of proteins). Pepsin is divided into another family of enzymes, each of which has its own functions.
- Mucus (it also protects the mucosa from destruction).
- Castle factor (an enzyme that helps to absorb B 12 ).
However, hydrochloric acid is still the main component of gastric juice. It will be discussed.
What is hydrochloric acid?
It is produced by the parietal cells of the glands of the stomach located on the body and the bottom of the organ. In fact, the mucous membrane is divided into several zones: one produces hydrochloric acid, the other produces bicarbonates that neutralize it. It is noteworthy that men have several times more parient cells than women.
The content of other acids in the stomach is negligible. So, if lactic acid is detected in it , this indicates that hydrochloric acid is produced in small quantities (lowered pH of the stomach) or is not produced at all. The latter may indicate serious failures such as oncology.
Hydrochloric acid in the stomach has a strict concentration level - it is 0.3-0.5% (or 160 mmol / l). Its composition is so concentrated that if there weren’t protective substances in the gastric juice and the mucous membrane, it would burn its own stomach. That is why with insufficient production of mucus by the stomach, a person develops gastritis or a duodenal ulcer. Acid is constantly present in the stomach, but its amount increases in response to food intake. The basal secretion of hydrochloric acid (i.e. morning) is 5-7 mmol / hour.
A healthy stomach produces up to 2.5 liters of hydrochloric acid per day!
Hydrochloric acid secretion has 3 phases.
- The reaction to the taste and smell of food. It is launched and transmitted from the central nervous system to the gastric cells through nerve endings.
- After food enters the body, a more significant phase begins. Gastrin acts on parietal cells, stimulating the production of hydrochloric acid.
- The final phase begins after the chyme (already digested food) enters the duodenum. Due to the increase in hydrochloric acid, the stomach produces somatostatin - its blocker.
What are the functions of hydrochloric acid in the stomach?
First of all, it improves digestion, destroys most of the bacteria that enter the stomach with food, which slows down or even interferes with the putrefactive process.
What are the functions of hydrochloric acid in the stomach? Below is a list detailing this issue.
- Protein denaturation (this is the destruction of their molecular structure) and their swelling.
- The activation of pepsinogen, which is converted to pepsin, is one of the most important enzymes that break down proteins.
- Creating an acidic environment in which enzymatic digestion is much easier.
- Evacuation of food from the stomach to the duodenum, where digestion continues.
- Antibacterial effect - many bacteria cannot live in such an aggressive environment.
- Excitation of pancreatic juice secretion.
Of particular note is the role of hydrochloric acid in the breakdown of proteins. The importance of proteins in the body is enormous. This question has been studied by scientists for many decades. It was found that hydrochloric acid in the stomach stimulates the production of pepsin, creating a favorable environment for its activity, and contributes to partial denaturation and swelling of proteins. In the duodenum, hydrochloric acid stimulates the secretion, improves iron absorption and has a bactericidal effect.
Proteins and gastric acidity
The role of hydrochloric acid in the digestion of proteins is still unclear. However, it was found that in inflammatory diseases of the stomach, its secretion is disrupted and, as a result, protein digestion.
The importance of proteins in our body is difficult to overestimate. This group is divided into many subgroups, each of which is engaged in its own business. So, hormone proteins control life processes (growth and reproduction), enzyme proteins provide chemical processes (respiration, digestion, metabolism), hemoglobin saturates the cells with oxygen.
Denaturation of proteins (this facilitates the process of their subsequent cleavage) allows the body to use their properties to the maximum. Each protein is composed of amino acids. Most of them are synthesized by our body, but there is a group of so-called essential amino acids that enter the body only from the outside.
Gastric acidity
Such an important aspect as the pH of the stomach directly depends on hydrochloric acid. And if there is a deviation from the norm, gastritis, dyspeptic disorders and other unpleasant conditions occur. The acidity in the stomach can be reduced, normal and increased.
Despite the “popularity” of high pH, people often have low or normal acidity. The latter is from 0.8 to 1.5.
Low stomach acid
Reduced acidity occurs with constant stress and inflammatory diseases. This happens due to the excitation of the sympathetic nervous system, which directly affects the production of gastric juice. A decrease in acidity leads to a deterioration in digestion and stomach spasm. Food remains in the cavity, begins to rot, increasing the reproduction of pathogenic bacteria. Man suffers from flatulence and nausea. The latter is a response to stomach spasm. Moreover, the process of absorption of all the nutrients contained in our food is actively disrupted, which leads to disruption of the entire body. By the way, it is on the basis of a natural decrease in pH after 40 years that a person begins to age rapidly. That is, hydrochloric acid in the stomach actually affects the health of the whole organism.
The stomach, surprised by the excessive growth of bacteria, begins to include a protective function, resulting in inflammation. He is treated with drugs that inhibit the production of hydrochloric acid even more - and the circle closes. A person is forced to constantly visit a doctor.
Even heartburn, which we are accustomed to consider a consequence of increasing the amount of gastric juice, is considered only a product of acetic acid fermentation.
In a sick stomach, lactic acid begins to form actively. Due to the inability of the stomach to produce a sufficient amount of mucus, it damages the walls of the organ. In such cases, the diagnosis is gastroduodenitis.
Parasites and low acidity of the stomach
Parasites cannot live in a healthy stomach (though this does not exclude their localization in other organs and systems of the body), since they are literally burned with hydrochloric acid. But as soon as it decreases, parasite colonies begin to thrive, causing extremely unpleasant symptoms. The absorption of nutrients is even more disturbed, there is a risk of food allergies (if the parasites "did not like" the food they eat).
Increased acidity of the stomach
Despite the opinion of many gastroenterologists, increased acidity is much less common than decreased. The danger is that with prolonged hypersecretion of gastric juice, ulcers of the esophagus and stomach appear. The patient is worried about heartburn and pain. Here, proton pump inhibitors, Omez and its analogues, will be useful. Symptoms are removed with the help of antacids - "Gaviscon", "Fosfalugel" and others.
To diagnose increased acidity, an instrumental examination is necessarily used , because by its symptoms it is easy to confuse it with a decreased secretion.
Types of determination of acidity of the stomach
Hydrochloric acid in the stomach (i.e. its level) is determined by several methods.
- Sounding. It is done using a special tube through which the contents of the stomach are aspirated.
- Intragastric pH. Sensors measure acidity directly in the stomach.
The second method is considered the most informative.
The acidity of the stomach is something that most doctors do not pay attention to, but in fact it is extremely important for the diagnosis and treatment of gastrointestinal diseases.