The bronchial tree in the structure is a trachea and bronchial trunks extending from it. The combination of these branches makes up the structure of the tree. The structure is identical for all people and has no striking differences. The bronchi are tubular branches of the main trachea that have the ability to conduct air and connect it to the respiratory parenchyma of the lung.
The structure of the main bronchi
The first branch of the trachea is the two main bronchi, which depart from it at almost a right angle, and each of them is directed towards the left or right lung, respectively. The bronchial system is asymmetrical and has slight differences in the structure of different sides. For example, the main left bronchus is slightly narrower in diameter than the right one, and has a greater length.
The structure of the walls of the main air-conducting trunks is the same as that of the main trachea, and they consist of a series of cartilaginous rings that are connected by a system of ligaments. The only distinguishing feature is that in the bronchi all the rings are always closed and have no mobility. In quantitative terms, the difference between the versatile trunks is determined by the fact that the right one has a length of 6-8 rings, and the left one is up to 12. Inside, all the bronchi are covered with a mucous membrane.
Bronchial tree
The main bronchi at their end begin to branch. Branching occurs on 16–18 smaller tubular leads. Such a system, due to its appearance, was called the "bronchial tree." The anatomy and structure of the new branches differ little from the previous departments. They are smaller and have a smaller diameter of the air paths. Such a branch is called lobar. Segmental follow, with branching into the lower, middle and upper lobar bronchi. And then they are divided into systems of apical, posterior, anterior segmental paths.
Thus, the bronchial tree branches more and more, reaching the 15th order of division. The smallest bronchi are lobular. Their diameter is only 1 mm. These bronchi are also divided into terminal bronchioles ending in respiratory. At their ends are the alveoli and alveolar passages. The system of respiratory bronchioles is a combination of alveolar passages and alveoli tightly adjacent to each other and forming the lung parenchyma.
In general, the wall of the bronchi consists of three membranes. These are: mucous, muscular-cartilaginous, adventitious. In turn, the mucous membrane is densely lined and has a multi-row structure, is covered with cilia, secrets, has its own neuroendocrine cells that can form and secrete biogenic amines, as well as cells involved in the regeneration of the mucosa.
Physiological functions
The main and most important function of the bronchus is to conduct air masses into the respiratory parenchyma of the lung and in the opposite direction. The bronchial tree is also a security system of the respiratory system and protects them from dust, various microorganisms, harmful gases. The regulation of the volume and speed of the air flow passing through the bronchial system is carried out when the difference between the pressure of the air in the alveoli and in the surrounding air changes. This effect is achieved due to the work of the respiratory muscles.
On inspiration, the diameter of the lumen of the bronchi changes in the direction of expansion, which is achieved by regulating the tone of smooth muscles, and on exhalation it is significantly reduced. Arising disturbances in the regulation of smooth muscle tone are both causes and consequences of many diseases associated with the respiratory system, such as asthma, bronchitis.
Dust particles entering the air, as well as microorganisms, are excreted by promoting the mucous secretions due to the cilia system in the direction of the trachea to the upper respiratory organs. The withdrawal of mucus containing impurities is due to cough.
Hierarchy
The branching of the bronchial system does not occur randomly, but follows a strictly established order. Hierarchy of the bronchi:
- The main ones.
- Zonal - second order.
- Segmented and subsegmented are the 3rd, 4th, 5th orders.
- Small - 6-15 orders.
- Terminal
This hierarchy is fully consistent with the division of lung tissue. So, lobar bronchi correspond to lung lobes, and segmental bronchi correspond to segments, etc.
Blood supply
Blood supply to the bronchi is carried out using arterial bronchial lobes of the thoracic aorta, as well as through the esophageal arteries. Venous blood is removed using unpaired and semi-unpaired veins.
Where are the human bronchi?
The chest contains many organs, vessels. Formed by the rib-muscle structure. It is designed to protect the most vital systems located inside it. Answering the question: “Where are the bronchi located?”, It is necessary to consider the location of the lungs, the blood vessels, lymphatic vessels and nerve endings connecting with them.
The dimensions of the human lungs are such that they occupy the entire front surface of the chest. The trachea and bronchi located in the center of this system are located under the anterior spine, located in the central part between the ribs. All bronchial leads are located under the costal mesh of the anterior sternum. The bronchial tree (its location scheme) associatively corresponds to the structure of the chest. So, the length of the trachea corresponds to the location of the central spinal column of the chest. And its branches are located under the ribs, which visually can also be defined as a branching of the central pillar.
Bronchial examination
Respiratory system tests include:
- Interrogation of the patient.
- Auscultation.
- X-ray examination.
- MRI of the lungs and bronchi.
Research methods, their purpose
When conducting a patient survey, possible factors are determined that can affect the state of the respiratory system, such as, for example, smoking, harmful working conditions. On examination, the doctor draws attention to the patient’s skin color, chest shape, inspiration rate, intensity, cough, shortness of breath, sounds unusual for normal breathing. They also palpate the chest, which can clarify its shape, volume, the presence of subcutaneous emphysema, the nature of voice trembling and the frequency of sounds. Deviation from the norm of any of these indicators indicates the presence of any disease, which is reflected in such changes.
Auscultation of the lungs is carried out using an endoscope and is performed to detect changes in respiratory sounds, wheezing, wheezing and other sounds uncharacteristic of normal breathing. Using this method, by ear, a doctor can determine the nature of the disease, the presence of swelling of the mucous membranes, sputum.
One of the most important roles in the study of diseases of the bronchial tree is played by x-rays. A panoramic x-ray of the human chest allows you to distinguish between the nature of the pathological processes that occur in the respiratory system. The structure of the bronchial tree is clearly visible and can be analyzed in order to identify pathological changes. The picture shows the changes occurring in the structure of the lungs, their extensions, bronchial lumens, thickening of the walls, the presence of tumor formations.
MRI of the lungs and bronchi is performed in anteroposterior and transverse projections. This makes it possible to examine and study the condition of the trachea and bronchi in their layered image, as well as in cross section.
Treatment methods
Modern treatment methods include both surgical and non-surgical treatment of diseases. It:
- Therapeutic bronchoscopy. It is aimed at removing bronchial contents and is performed in a treatment room, under the influence of local or general anesthesia. First of all, the trachea and bronchi are considered to establish the nature and area of damage from the effects of inflammatory changes. Then washing is carried out with indifferent or antiseptic solutions, medicinal substances are introduced.
- Remediation of the bronchial tree. This method is the most effective of the known and includes a number of procedures aimed at cleansing the bronchial tract from excess mucus, eliminating inflammatory processes. For this, you can use: chest massage, the use of expectorants, the installation of special drainage up to several times a day, inhalation.
Providing the body with oxygen, and therefore, ensuring the body's ability to live is due to the coordinated work of the respiratory system and blood supply. The relationship of these systems, as well as the speed of the processes determine the ability of the body to control and carry out various processes in it. With a change or violation of the physiological processes of respiration, a negative effect is exerted on the state of the whole organism as a whole.