Bodies of human respiration. Structure and function of the respiratory system

What can be called the main indicator of the viability of people? Of course, we are talking about breathing. A person can do without food and water for a while. Without air, vital activity is not possible at all.

General information

What is breathing? This is the link between the environment and people. If air intake for any reason is difficult, then the heart and respiratory organs of a person begin to function in an enhanced mode. This is due to the need to provide enough oxygen. The organs of the respiratory system are able to adapt to the conditions of a volatile environment.

Interesting Facts

Scientists were able to establish that air entering the respiratory system of a person forms two streams (conditionally). One of them penetrates into the left side of the nose. A study of the respiratory system shows that the second passes from the right side. Specialists have also proved that the brain arteries have a separation into two streams of air production. Therefore, the respiratory process must be correct. This is very important for maintaining normal life of people. Consider the structure of the human respiratory system.

Important Features

When talking about breathing, we are talking about a set of processes that are aimed at ensuring the continuous supply of all tissues and organs with oxygen. In this case, substances that form during the exchange of carbon dioxide are removed from the body. Breathing is a very complex process. It goes through several stages. The stages of entry and exit of air into the body are as follows:

1. Ventilation of the lungs. It is a question of gas exchange between atmospheric air and alveoli. This stage is considered an external breath.
2. Exchange of gases in the lungs. It occurs between the blood and the alveolar air.
3. Two processes: the delivery of oxygen from the lungs to the tissues, as well as transport of carbon dioxide from the latter to the first. That is, we are talking about the movement of gases through blood flow.
4. The next stage of gas exchange. It involves tissue cells and blood capillaries.
5. Finally, the inner breath. This refers to the biological oxidation that occurs in the mitochondria of cells.

Main goals

Human respiratory organs provide removal of carbon dioxide from the blood. Their task is also to saturate it with oxygen. If you list the functions of the respiratory system, then this is the most important.

Additional appointment

There are other functions of the human respiratory system, among them we can distinguish such:

1. Participation in the processes of thermoregulation. The fact is that the temperature of the inhaled air influences the analogous parameter of the human body. During exhalation the body gives heat to the external environment. At the same time, it cools, if possible.
2. Participation in excretory processes. During exhalation, together with the air, water vapor is eliminated from the body (except carbon dioxide). This also applies to some other substances. For example, ethyl alcohol during alcoholic intoxication.
3. Participation in immune reactions. Due to this function of the human respiratory system, it becomes possible to neutralize some pathologically dangerous elements. They include, in particular, pathogenic viruses, bacteria and other microorganisms. This ability is endowed with certain lung cells. In this regard, they can be attributed to the elements of the immune system.

Specific tasks

There are very narrowly focused functions of the respiratory system. In particular, specific tasks are performed by the bronchi, trachea, larynx, nasopharynx. Among such narrowly focused functions, one can single out the following:

1. Cooling and warming of incoming air. This task is carried out in accordance with the ambient temperature.
2. Humidification of the air (inhaled), which prevents the drying of the lungs.
3. Purification of incoming air. In particular, this applies to foreign particles. For example, to the dust coming in with the air.

Structure of the human respiratory system

All elements are connected by special channels. On them enters and leaves the air. Also, this system includes the lungs - the organs where gas exchange takes place. The device of the whole complex and the principle of its operation are rather complicated. Consider the human respiratory system (pictures are shown below) in more detail.

Information about nasal cavity

Breathing paths begin with it. The nasal cavity is separated from the oral cavity. The front is a hard sky, and the back is soft. The nasal cavity has a cartilaginous and bony skeleton. It is divided into left and right parts thanks to a solid partition. Also there are three nasal shells. Thanks to them the cavity is divided into passages:

1. Lower.
2. Average.
3. Upper.

Exhaled and inhaled air passes through them.

Features of the mucosa

It has a number of devices that are designed to treat inhaled air. First of all, it is covered by the ciliated epithelium. His cilia formed a continuous carpet. Due to the fact that the cilia flicker, the dust is easily eliminated from the nasal cavity. Hairs that are at the outer edge of the holes also contribute to the retention of foreign elements. The mucous membrane contains special glands. Their secret envelops the dust and helps to eliminate it. In addition, the air is humidified.

Slime, which is located in the nasal cavity, has bactericidal properties. It contains lysozyme. This substance helps reduce the ability of bacteria to multiply. It also kills them. In the mucosa there are many venous vessels. Under different conditions, they can swell. If they are damaged, then nosebleeds begin. The purpose of these formations is to heat the air stream passing through the nose. Leukocytes leave the blood vessels and are on the surface of the mucosa. They also perform protective functions. In the process of phagocytosis, leukocytes die. Thus, in the mucus that stands out from the nose, there are many dead "defenders". Then the air passes into the nasopharynx, and from there - into the other organs of the respiratory system.

Larynx

It is in the anterior laryngeal part of the pharynx. This is the level of the 4th-6th cervical vertebrae. The larynx is formed by cartilages. The latter are divided into paired (wedge-shaped, carobiform, arytenoid) and unpaired (cricoid-shaped, thyroid-shaped). The epiglottis is attached to the upper edge of the last cartilage. During swallowing, he closes the entrance to the larynx. Thus, it prevents food from getting into it.

Two vocal cords go from the thyroid to the arytenoid cartilage. The voice gap is the space that forms between them.

General information about the trachea

It is a continuation of the larynx. It is divided into two bronchial tubes: left and right. Bifurcation is the place where the trachea branches. It is characterized by the following length: 9-12 centimeters. On average, the transverse diameter reaches eighteen millimeters.

A trachea can include up to twenty incomplete cartilaginous rings. They are connected by means of fibrous ligaments. Thanks to cartilaginous semirings, the airways become elastic. In addition, they are made flowing, therefore, easily passable for air.

The membranous posterior wall of the trachea is flattened. It contains smooth muscle tissue (bundles that run longitudinally and transversely). Thanks to this, an active movement of the trachea is provided for coughing, breathing, and so on. As for the mucous membrane, it is covered by the ciliated epithelium. In this case, the exception is part of the epiglottis and vocal cords. It also has mucous glands and lymphoid tissue.

Bronchi

This is a doubled element. Two bronchi, divided by the trachea, enter the left and right lungs. There, they branch tree-like branches into smaller elements, which are included in the pulmonary lobules. So, bronchioles are formed. We are talking about even smaller respiratory branches. The diameter of the respiratory bronchioles can be 0.5 mm. They, in turn, form alveolar courses. The latter end with appropriate bags.

What are the alveoli? These are protrusions that look like bubbles, which are located on the walls of the corresponding sacs and passages. Their diameter reaches 0.3 mm, and the number can reach up to 400 million. This provides the possibility of creating a large respiratory surface. This factor significantly affects the volume of the lungs. The latter can be increased.

The most important organs of human respiration

They are considered to be the lungs. Serious diseases associated with them can endanger life. Light (photos are presented in the article) are in the thoracic cavity, which is hermetically sealed. Its posterior wall is formed by the corresponding spine and ribs, which are attached movably. Between them are internal and external muscles.

The thoracic cavity is separated from the ventral cavity from below. This involves a flagellate obstruction, or diaphragm. Anatomy of the lungs is not simple. The man has two. The right lung includes three parts. At the same time, the left consists of two. The tip of the lungs is their narrowed upper part, and the enlarged lower one is considered the base. The gates are different. They are represented by indentations on the inner surface of the lungs. Through them pass blood vessels, bronchi, nerves, and also lymphatic vessels. The root is represented by a combination of the above formations.

Light (photo illustrates their location), more precisely their fabric, consist of small structures. They are called lobules. These are small areas with a pyramidal shape. Bronchi, which enter the corresponding lobule, are divided into respiratory bronchioles. Alveolar course is at the end of each of them. This whole system is a functional unit of the lungs. It is called the acinus.

The lungs are covered with pleura. This is a shell consisting of two elements. These are external (parietal) and internal (visceral) petals (the lung scheme is attached below). The latter covers them and at the same time is the outer shell. He makes the transition to the outer pleura in the root and represents the inner shell of the walls of the chest cavity. This leads to the formation of a geometrically closed smallest capillary space. It's about the pleural cavity. It contains a small amount of the corresponding liquid. She wets the pleura. This makes it easier to slide between them. Change of air in the lungs occurs for many reasons. One of the main changes is the size of the pleural and thoracic cavities. This is the anatomy of the lungs.

Features of the air inlet and outlet mechanism

As already mentioned earlier, between the gas that is in the alveoli, and the atmosphere is exchanged. This is due to the rhythmic alternation of breaths and exhalations. Lungs do not have muscle tissue. For this reason, their intensive reduction is impossible. In this case, the most active role is given to the respiratory muscles. With their paralysis, inhaling is not possible. In this case, the respiratory system is not affected.

Inspiration is an act of inspiration. This is an active process, during which the chest is enlarged. Expiration is an act of exhalation. This process is passive. It occurs due to the fact that the chest cavity decreases.

The respiratory cycle is represented by the phases of inspiration and the subsequent exhalation. In the process of entering the air, the diaphragm and the external oblique muscles participate. With their reduction, the ribs begin to rise. At the same time, there is an increase in the chest cavity. The aperture is shortened. In this case, it takes a more flat position.

As for incompressible abdominal organs, during the process under consideration they are pushed aside and down. The dome of the diaphragm, with a quiet breath, drops about one and a half centimeters. Thus, there is an increase in the vertical size of the thoracic cavity. In the case of very deep breathing, auxiliary muscles take part in the inspiratory act, among which are the following:

1. Rhomboid (which lifts the scapula).
2. Trapezoidal.
3. Small and large pectorals.
4. Front serrated.

The wall of the thoracic cavity and lungs is covered by the serous membrane. The pleural cavity is represented by a narrow slit between the leaves. It contains serous fluid. Lungs are always in a stretched state. This is due to the fact that the pressure in the pleural cavity is negative. It is a question of elastic draft. The fact is that the lung volume constantly tends to decrease. At the end of a quiet exhalation, almost every respiratory muscle relaxes. The pressure in the pleural cavity is below atmospheric pressure. In different people, the main role in the act of inspiration is played by the diaphragm or intercostal muscles. In accordance with this, we can talk about different types of breathing:

1. The costal.
2. Diaphragmatic.
3. Abdominal.
4. Thoracic.

At present, it is known that women have the last type of respiration. In most men, the abdominal is observed. During quiet breathing, exhalation is due to elastic energy. It accumulates during the previous inspiration. When the muscles relax, the ribs can passively return to their original position. If the contractions of the diaphragm decrease, it will take its former dome-like position. This is due to the fact that the organs of the abdominal cavity affect it. Thus, the pressure in it decreases.

All of the above processes lead to squeezing the lungs. Out of them comes air (passively). Exhaled exhalation is an active process. Internal intercostal muscles participate in it. At the same time, their fibers go in the opposite direction, if compared with the external. They contract and the ribs go down. There is also a decrease in the chest cavity.