The bronchi are defined as a series of tubes that form part of the structure of the respiratory system. There are two main bronchi, which arise at the end of the trachea and each leads towards a lung. In turn, the lobar bronchi and the smaller bronchioles take control of the interior of the lungs.
When air enters the body, it follows the path of the trachea and bronchi so that gas exchange is guaranteed at the blood level and thus allows oxygenation of tissues throughout the body. The wall of these structures is composed of cartilage and muscular, elastic and mucous layers.
The main bronchi have their origin in the bifurcation that the trachea has at its lower extremity, one right and the other left, from there these structures go to the corresponding lung through a series of divisions in the form of branches until finally reaching the tubular structures. of very small diameter that are known as bronchioles, which finally give rise to the functional unit of the lung that is called the alveolus.
These structures are formed by an internal layer or mucous membrane, which in turn is made up of structures that are in the form of hairs called cilia, the so-called beautiful ones have the function of performing a sweeping movement that is directed towards the outside in order to maintain the airway clean and free of secretions, foreign objects such as dust and microorganisms that can be introduced into it.
On the periphery, the bronchi are made up of smooth muscle surrounded by cartilage, which allows them to increase or decrease their diameter, always remaining permeable . It is important to note that the bronchi are the seat of a wide range of diseases, the most frequent being the infections known as bronchitis in adults and bronchiolitis in children. In the specific case of bronchitis, they can be caused by viruses and also by bacteria and their main symptom is cough, which can be dry or wet depending on the presence or absence of secretion.