Man is the most mysterious and studied organism on planet Earth. Each of its organs has its own task and continuously performs its functions: the heart pumps blood throughout the body, the lungs provide breathing, the esophagus and stomach are responsible for replenishing supplies, and the brain processes all information. Consider the function of the organs of the chest cavity in the human body.
Chest cavity
The chest cavity is the space in the body that is located inside the chest. The chest and abdominal cavities separate the internal organs that are in them from the skeleton and muscles of the body, allowing these organs to move smoothly inside relative to the walls of the body. Organs located in the chest cavity: heart, vessels and nerves, trachea, bronchi and lungs; the esophagus passes from the chest cavity into the abdominal cavity through an opening in the diaphragm. The abdominal cavity contains the stomach and intestines, liver, kidneys, spleen,pancreas, numerous vessels and nerves.
The photo shows where and what organs of the chest cavity are located. The heart, trachea, esophagus, thymus, large vessels and nerves are located in the space between the lungs - in the so-called mediastinum. Attached to the lower ribs, posterior sternum, and lumbar vertebrae, the domed diaphragm forms a barrier between the human thoracic and abdominal organs.
Heart
The most working muscle of the human body is the heart or myocardium. The heart is measured, with a certain rhythm, without stopping, overtakes the blood - about 7200 liters daily. Different parts of the myocardium simultaneously contract and relax at a frequency of about 70 times per minute. With intensive physical work, the load on the myocardium can triple. The heart's contractions are triggered automatically by a natural pacemaker located in its sinoatrial node.
Myocardium works automatically and is not subject to consciousness. It is formed by many short fibers - cardiomyocytes, interconnected into a single system. Its work is coordinated by a system of conductive muscle fibers of two nodes, one of which houses the center of rhythmic self-excitation - the pacemaker. It sets the rhythm of contractions, which can change under the influence of nerve and hormonal signals from other parts of the body. For example, with a heavy load, the heart beats faster, directing more blood to the muscles per unit of time. Thanks to himperformance through the body for 70 years of life passed about 250 million liters of blood.
Trachea
This is the first of the human thoracic organs. This organ is designed to pass air into the lungs and is located in front of the esophagus. The trachea starts at the height of the sixth cervical vertebra from the cartilage of the larynx and branches into the bronchi at the height of the first thoracic vertebra.
The trachea is a tube 10-12 cm long and 2 cm wide, consisting of two dozen horseshoe-shaped cartilages. These cartilage rings are held anteriorly and laterally by ligaments. The gap of each horseshoe ring is filled with connective tissue and smooth muscle fibers. The esophagus is located just behind the trachea. Inside the surface of this organ is covered with a mucous membrane. The trachea, dividing, forms the following organs of the human chest cavity: the right and left main bronchi, descending into the roots of the lungs.
Bronchial tree
Branching in the form of a tree contains the main bronchi - right and left, partial bronchi, zonal, segmental and subsegmental, small and terminal bronchioles, behind them are the respiratory sections of the lungs. The structure of the bronchi varies throughout the bronchial tree. The right bronchus is wider and placed steeper downwards than the left bronchus. Above the left main bronchus is the aortic arch, and below and in front of it is the pulmonary trunk of the aorta, which divides into two pulmonary arteries.
The structure of the bronchi
The main bronchi diverge, creating 5 lobar bronchi. From them further go 10segmental bronchi, each time decreasing in diameter. The smallest branches of the bronchial tree are bronchioles with a diameter of less than 1 mm. Unlike the trachea and bronchi, bronchioles do not contain cartilage. They consist of many smooth muscle fibers, and their lumen remains open due to the tension of the elastic fibers.
The main bronchi are perpendicular and rush to the gates of the corresponding lungs. At the same time, the left bronchus is almost twice as long as the right one, has a number of cartilaginous rings 3-4 more than the right bronchus, and seems to be a continuation of the trachea. The mucous membrane of these organs of the chest cavity is similar in structure to the mucous membrane of the trachea.
The bronchi are responsible for passing air from the trachea to the alveoli and back, as well as cleansing the air of foreign impurities and removing them from the body. Large particles leave the bronchi during coughing. And small particles of dust or bacteria that have penetrated into the respiratory organs of the chest cavity are removed by the movements of the cilia of epithelial cells that promote the bronchial secretion towards the trachea.
Light
In the chest cavity there are organs that everyone calls the lungs. This is the main paired respiratory organ, which occupies most of the chest space. Separate the right and left lungs according to location. In their shape, they resemble cut cones, with the top directed towards the neck, and the concave base towards the diaphragm.
The top of the lung is 3-4 cm above the first rib. The outer surface is adjacent to the ribs. ATthe lungs lead to the bronchi, pulmonary artery, pulmonary veins, bronchial vessels and nerves. The place of penetration of these organs is called the gates of the lung. The right lung is wider but shorter than the left. The left lung in the lower front part has a niche under the heart. The lung contains a significant amount of connective tissue. It has a very high elasticity and helps to work the contractile forces of the lungs, which are needed with each inhalation and exhalation.
Lung Capacity
At rest, the volume of inhaled and exhaled air averages about 0.5 liters. The vital capacity of the lungs, that is, the volume at the deepest exhalation after the deepest breath, is in the range from 3.5 to 4.5 liters. For an adult, the rate of air consumption per minute is approximately 8 liters.
Aperture
Respiratory muscles rhythmically increase and decrease the volume of the lungs, changing the size of the chest cavity. The main work is done by the diaphragm. As it contracts, it flattens and descends, increasing the size of the chest cavity. The pressure in it drops, the lungs expand and draw in air. This is also facilitated by the lifting of the ribs by the external intercostal muscles. With deep and accelerated breathing, auxiliary muscles are involved, including the pectoral and abdominal muscles.
The mucous membrane of these organs of the chest cavity consists of epithelium, which, in turn, consists of many goblet cells. In the epithelium of the branches of the bronchial treethere are many endocrine cells that control the blood supply to the lungs and keep the bronchial muscles in good shape.
Summing up all of the above, it should be noted that the organs of the human chest cavity are the basis of his life. It is impossible to live without a heart or lungs, and the violation of their work leads to serious diseases. But the human body is a perfect mechanism, you just need to listen to its signals and not harm, but help Mother Nature in its treatment and recovery.
