Lungs are the vitals supplying our organism with oxygen. Functioning of all organism depends on their correct work. The mechanism of work of lungs is rather difficult.
Instruction
1. Lungs are quite volume respiratory organs occupying by themselves almost all chest cavity of the person. At a breath oxygen from lungs comes to blood, and the carbon dioxide formed in an organism from blood goes back to lungs and is removed at an exhalation.
2. At a breath and an exhalation the lungs extend and clench as they are covered with a special cover – a pleura. Besides, under lungs the special flat muscle called a diaphragm is located. On a breath the diaphragm and intercostal muscles strain, edges rise, and the diaphragm falls. As a result the thorax size considerably increases, the volume of lungs grows, lungs involve the air containing necessary oxygen. On an exhalation, on the contrary, intercostal muscles relax, edges, falling, move down, and the diaphragm rises, forcing out from lungs air with carbon dioxide.
3. At a breath air at first gets into a trachea which passes into two tubules called bronchial tubes. Bronchial tubes, in turn, branch on smaller branches – bronchioles. The terminations of bronchioles are filled with vials of air. These are tiny pulmonary bubbles, or alveoluses. Through their thin walls oxygen from lungs comes to the blood flowing on blood vessels. Alveoluses form clusters. In lungs of the person there are about three hundred million alveoluses.
4. Each alveolus is covered with a network of the smallest blood vessels – capillaries. They represent network which is engaged in direct delivery of blood to pulmonary arteries and veins. Pulmonary veins and arteries take part in the system of a so-called small circle of blood circulation of an organism.
5. The pulmonary artery and its branches deliver in alveolar capillaries blood with the high content of carbon dioxide, poor in oxygen. In alveoluses there is a simultaneous movement of carbon dioxide from blood and in air, and oxygen – from air in blood. The blood oxygenated comes on a pulmonary vein to heart, from there up to an artery disperses on the vessels going to all fabrics and human organs and feeding them.
6. Healthy lungs – pledge of the fact that all tissues of the person in due time and in sufficient volume are supplied with oxygen. Vital capacity of lungs of the healthy person has to be not less than three quarters of the total amount of lungs. Healthy lungs are not only a consequence of good heredity, but also result correct, the healthy lifestyle meaning attention to a condition of the organism.