What is gas exchange in the blood, in the lungs and tissues? Features of gas exchange

What is gas exchange? Almost no living creature can do without it. Gas exchange in the lungs and tissues, as well as blood helps to saturate cells with nutrients. Thanks to him, we get energy and vitality.

What is gas exchange?

Living organisms need air for living. It is a mixture of many gases, the major part of which is oxygen and nitrogen. Both these gases are the most important components for ensuring the normal life of organisms.

In the course of evolution, different species developed their adaptations for their production, some developed lungs, others had gills, and others only used skin. With the help of these organs gas exchange is carried out.

What is gas exchange? This is the process of interaction of the environment and living cells, during which there is an exchange of oxygen and carbon dioxide. During breathing, oxygen enters the body along with air. Saturating all cells and tissues, it participates in the oxidative reaction, turning into carbon dioxide, which is excreted from the body together with other metabolic products.

Gas exchange in the lungs

Every day we inhale more than 12 kilograms of air. The lungs help us in this. They are the most voluminous organ, capable of accommodating up to 3 liters of air in one full deep breath. Gas exchange in the lungs occurs with the help of alveoli - numerous vesicles, which are intertwined with blood vessels.

Air enters them through the upper respiratory tract, passing through the trachea and bronchi. Combined with the alveoli, capillaries take air and carry it through the circulatory system. At the same time, they give the alveoli carbon dioxide, which leaves the body together with the exhalation.

The process of exchange between the alveoli and the vessels is called two-way diffusion. It occurs in just a few seconds and is due to the difference in pressure. At oxygen-saturated atmospheric air it is larger, so it rushes to the capillaries. Carbon dioxide has a lower pressure, which is why it is pushed into the alveoli.

Circulation

Without a circulatory system, gas exchange in the lungs and tissues would not be possible. Our body is permeated with a variety of blood vessels of different length and diameter. They are represented by arteries, veins, capillaries, venules, etc. In blood vessels, blood circulates continuously, facilitating the exchange of gases and substances.

Gas exchange in the blood is carried out with the help of two circles of blood circulation. When breathing, air starts to move along a large circle. In the blood it is transferred, attaching to a special protein hemoglobin, which is contained in red blood cells.

From the alveoli, air enters the capillaries, and then into the arteries, heading straight for the heart. In our body, it acts as a powerful pump, pumping oxygenated blood to tissues and cells. They, in turn, give blood, filled with carbon dioxide, directing it along the veins and veins back to the heart.

Passing through the right atrium, venous blood completes a large circle. In the right ventricle begins a small circle of blood circulation. On it the blood is distilled into the pulmonary trunk. It moves along arteries, arterioles and capillaries, where it makes air exchange with the alveoli to start the cycle anew.

Exchange in tissues

So, we know what is the gas exchange of the lungs and blood. Both systems transfer gases and exchange them. But the key role belongs to the tissues. They are the main processes that change the chemical composition of air.

Arterial blood saturates cells with oxygen, which triggers a whole series of oxidation-reduction reactions. In biology they are called the Krebs cycle. For their implementation, enzymes are needed, which also come with blood.

During the Krebs cycle , lemon, acetic and other acids are formed, products for the oxidation of fats, amino acids and glucose. This is one of the most important stages that accompanies gas exchange in tissues. During its course, the energy necessary for the operation of all organs and systems of the body is released.

Oxygen is actively used for the reaction. Gradually, it oxidizes, turning into carbon dioxide - CO ₂ , which is released from cells and tissues into the bloodstream, then into the lungs and atmosphere.

Gas exchange in animals

The structure of the organism and organ systems in many animals varies considerably. The most similar to humans are mammals. Small animals, such as planaria, do not have complex systems for the exchange of substances. For breathing, they use outer covers.

Amphibians for respiration use the skin, as well as the mouth and lungs. In most animals living in water, gas exchange is carried out with the help of gills. They are thin plates connected to capillaries and transferring oxygen from them in water.

Arthropods, for example, centipedes, lice, spiders, insects, do not have lungs. On the entire surface of the body they have trachea, which direct air directly to the cells. Such a system allows them to move quickly without experiencing shortness of breath and fatigue, because the process of energy generation occurs faster.

Exchange of gases in plants

Unlike animals, in plants gas exchange in tissues involves the consumption of both oxygen and carbon dioxide. Oxygen they consume in the process of breathing. Plants do not have special organs for this, so air enters them through all parts of the body.

As a rule, the leaves have the largest area, and the main amount of air falls on them. Oxygen enters them through small holes between the cells, called stomata, is processed and discharged already in the form of carbon dioxide, as in animals.

A distinctive feature of plants is the ability to photosynthesis. So, they can convert inorganic components into organic ones using light and enzymes. During photosynthesis, carbon dioxide is absorbed and oxygen is produced, so plants are real "factories" for air enrichment.

Features

Gas exchange is one of the most important functions of any living organism. It is carried out with the help of breathing and circulation, contributing to the release of energy and metabolism. The peculiarities of gas exchange are that it does not always flow in the same way.

First of all, it is impossible without breathing, its stop for 4 minutes can lead to disruption of the brain cells. As a result, the body dies. There are many diseases in which there is a violation of gas exchange. Tissues do not get enough oxygen, which slows down their development and function.

Uneven gas exchange is observed in healthy people. It increases significantly with increased muscle work. Literally in six minutes he reaches the maximum power and adheres to it. However, when the load is increased, the amount of oxygen can start to increase, which will also be unpleasant for the body.