Respiratory system. Structure, bronchial and lung function, causes of pain

Bronchi and lungs. Structure

Bronchs are called all branches that depart from the trachea. In their totality they form a "bronchial tree". It has its own orderly hierarchy, which in all people is the same.

In the place of separation of the trachea, at almost a right angle, a pair of main bronchi exits from it, each of which is directed to the gates of the left and right lungs, respectively. Their form is not the same. So, the left bronchus is almost twice as long as the right and already. This narrowness is the cause of the most rapid penetration of infectious agents into the lower respiratory tract through the shorter and wider main right bronchus. The walls of these branches are arranged like the walls of the trachea and consist of connected cartilaginous rings. However, unlike the trachea, the cartilaginous bronchial rings are always closed. In the wall of the left branch there are from nine to twelve rings, in the wall of the right branch - from six to eight. The inner surface of the main bronchi is covered with a mucous membrane, the structure and functions of which are similar to the mucosa of the trachea. The branches of the lower link depart from the main branches (in accordance with the hierarchy). They include:

Bronchus of the second link (zonal),

Bronchi from the third to the fifth link (segmental and subsegmental),

Bronchi from the sixth to the fifteenth link (small)

And terminal bronchioles associated directly with the lung tissue (they are the thinnest and smallest). They pass into the pulmonary alveoli and respiratory passages.

Ordinal division of the bronchial tree corresponds to the division of lung tissue.

Lungs belong to the terminal section of the respiratory system and are a paired respiratory organ. They are located in the chest cavity on each side of the complex of organs, consisting of the heart, the aorta, the superior vena cava and other organs of the mediastinum. The lungs, in contact with the front wall of the chest and spine, occupy a large space in the chest cavity. The shape of the right and left parts is not the same. This is due to the fact that under the right lung is the liver, and on the left is the heart in the chest cavity. Thus, the right part is shorter and wider, and its volume is larger than the volume of the left part by ten percent. The lungs are located in the right and left pleural sac respectively. Pleura - thin film, which consists of connective tissue. It covers the chest cavity both from the inside and outside (in the area of the lungs and mediastinum). Between the inner and outer films there is a special lubricant, which significantly reduces the frictional force during breathing. The lungs have a conical shape. The apex of the organ protrudes slightly (two to three centimeters) because of the clavicle or the first rib. Their posterior border is located in the region of the seventh cervical vertebra. The lower limit is determined by percussion.

Functions

Bronch is the organ that is primarily responsible for delivering air to the pulmonary alveoli from the trachea. In addition, he takes part in the formation of a cough reflex, with the help of which small foreign bodies and large dust particles are removed from it. The protective functions of the bronchus are provided by the presence of cilia and a large amount of excreted mucus. Due to the fact that these organs in children are shorter and narrower than in adults, their obstruction by swelling and masses of mucus is easier. The function of the bronchus also includes the processing of incoming atmospheric air. These organs moisturize and warm it.

In contrast, bronchus, the lungs are responsible for the direct supply of oxygen into the blood, through the respiratory alveocytes and membranes of the alveoli.

Often there are complaints of pain in the bronchi. In this case, the cause of their occurrence should be established. Such sensations can be caused either by pulmonary infections, or by any other reasons. However, it should be noted that neither lung tissue nor bronchi have sensitive nerves, so they can not "ache". The reason may be neuralgic, muscle or bone character.