bronchialträdet

The bronchial tree, also known as the tracheobronchial tree, refers to the branching network of airways in the respiratory system that conducts air from the trachea into the lungs. It begins with the trachea, which then divides into two main bronchi, the right and left primary bronchi, leading into the respective lungs.

Each primary bronchus further subdivides into secondary bronchi, also called lobar bronchi, supplying air to the different lobes of the lungs. The right lung has three lobes, thus three secondary bronchi, while the left lung has two lobes, resulting in two secondary bronchi.

These secondary bronchi continue to divide into tertiary bronchi, or segmental bronchi, which supply air to specific segments within each lobe. This process of branching continues repeatedly, creating smaller and smaller airways. The bronchioles are the smallest airways, lacking cartilage and characterized by smooth muscle in their walls.

The terminal bronchioles are the final conducting airways, leading into the respiratory bronchioles. These then lead into alveolar ducts, which open into alveolar sacs and alveoli, where gas exchange (oxygen and carbon dioxide) takes place. The entire bronchial tree is lined with pseudostratified ciliated columnar epithelium, which helps to trap and remove foreign particles from the airways. This intricate structure ensures efficient delivery of air to the vast surface area of the alveoli for respiration.