Lungs

The structure of the lungs

Easy - the authority to ensure the person's breathing. These paired organs located in the chest cavity, adjacent to the left  Human lungs
 and right to the heart. Lungs have the form of half-cone, the base adjacent to the diaphragm, the tip protruding above the clavicle 2-3 cm. The right lung has three lobes, the left - two. The skeleton consists of a tree-like light branching bronchi. Each light covers the outside serosa - pulmonary pleura. Lungs are in the pleural sac formed by the pulmonary pleura (visceral) and the lining inside the chest cavity parietal pleura (parietal). Each outside the pleura contains gland cells that produce the fluid in the cavity between the sheets of pleura (pleural cavity). On the inside (cardiac) surface of each light has a groove - gate lungs. At the gates of the lungs are the bronchi and pulmonary artery and pulmonary veins out two. Pulmonary artery branch of the parallel bronchi.

Lung tissue is composed of lobules pyramid-shaped base facing surface. At the top of each part of the bronchus segments sequentially to produce fissile terminal bronchioles (18-20). Each bronchiole ends acini - structural and functional element of light. Acini consist of alveolar bronchioles, which are divided into alveolar ducts. Each course ends with two alveolar air sacs.

Alveoli - a hemispherical protrusion consisting of connective tissue fibers. They are lined with a layer of epithelial cells and richly braided blood capillaries. It is carried out mainly in the alveoli lung function - the processes of gas exchange between the atmospheric air and blood. Thus as a result of diffusion of oxygen and carbon dioxide, overcoming the diffusion barrier (alveolar epithelium, basement membrane, blood capillary walls) from the erythrocytes to penetrate the alveoli and vice versa.

Lung Function

The most important function of the lung is the gas exchange - hemoglobin oxygen supply, the output of carbon dioxide. Receipt of oxygen-enriched air and the withdrawal of carbonated carried out thanks to active movement of the chest and diaphragm, and the contractility of the lungs themselves. But there are other lung function. The lungs are actively involved in maintaining the desired concentration of ions in the body (acid-alkaline balance), can display many substances (aromatics, esters and others). Also easily regulate the water balance of the body: through the lungs evaporates about 0, 5 liters of water per day. In extreme situations (eg, hyperthermia), this figure can reach up to 10 liters per day.

Ventilation is carried out due to the pressure difference. Inspiratory lung pressure is much lower than atmospheric pressure, so that the air penetrates into the lungs. During exhalation the pressure in the lungs above atmospheric.

There are two types of breathing: rib (breast) and diaphragmatic (abdominal).

Rib breathing

The edges of the attachment to the vertebral column are pairs of muscles, which are attached at one end to the vertebra, and the other - to the edge. There are internal and external intercostal muscles. External intercostal muscles provide a process of inspiration. Exhale normally a passive and in the pathology of the act of exhalation helps internal intercostal muscles.

Diaphragmatic breathing

Diaphragmatic breathing is carried out with the participation of the diaphragm. In the relaxed condition the diaphragm has a dome shape. With the reduction of its muscle dome is flattened, the volume of the thoracic cavity is increased while the pressure in the lungs is reduced compared to atmospheric pressure and carried out a breath. If diaphragmatic muscle relaxation as a result of the pressure difference diaphragm again takes its initial position.

Regulation of breathing

Breathing is regulated by centers of inhalation and exhalation. The respiratory center is located in the medulla oblongata. Receptor mediated regulation of respiration, are located in the walls of blood vessels (chemoreceptors sensitive to the concentration of carbon dioxide and oxygen) and on the walls of the bronchi (receptors sensitive to pressure changes in the bronchi - baroreceptors). There are also receptive fields in the carotid sinus (spot discrepancies internal and external carotid arteries).

Light smoker

In the process of smoking are easily swiped. Tobacco smoke, penetrates into the lungs of a smoker, comprising tobacco tar (tar), hydrogen cyanide, nicotine. All these substances are deposited in the lung tissue, resulting in lung epithelium it begins simply die. Light smoker is a dirty-gray  pneumonia
 or even just a black mass of dying cells. Of course, the functionality of such light is significantly reduced. In the lungs of a smoker developing ciliary dyskinesia occurs spasms of the bronchi, resulting in bronchial secretions accumulate, develop chronic pneumonia, bronchiectasis formed. All this leads to the development of COPD - chronic obstructive pulmonary disease.

pneumonia

One of the most common severe lung disease is an inflammation of the lungs - pneumonia. The term "pneumonia" includes a group of diseases with different etiology, pathogenesis, clinical. Classical bacterial pneumonia is characterized by hyperthermia, cough with purulent sputum department, in some cases (with involvement of the visceral pleura) - pleural pain. With the development of pneumonia is an expansion of the lumen of the alveoli, the accumulation of fluid in them exudative, penetration into these red blood cells, filling alveolar fibrin, leukocytes. For the diagnosis of bacterial pneumonia using radiographic techniques, microbiological sputum examination, laboratory tests, the study of blood gas. The mainstay of treatment is antibiotic therapy.





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