keuhkoputkistoon

Keuhkoputkisto, known scientifically as the bronchial tree or tracheobronchial tree, refers to the branching system of airways within the lungs that conduct air to and from the alveoli. It begins with the trachea, or windpipe, which bifurcates into the left and right primary bronchi. These primary bronchi then further divide into secondary, or lobar, bronchi, supplying air to the different lobes of each lung.

The branching continues progressively, creating smaller and smaller tubes. Tertiary, or segmental, bronchi are formed, followed by bronchioles, which are very narrow airways lacking cartilage. The smallest of these are the terminal bronchioles, which lead into respiratory bronchioles. These respiratory bronchioles are the final conducting airways and mark the transition to the gas exchange areas of the lungs.

Embedded within the walls of the larger bronchi are C-shaped rings of cartilage that provide structural support and prevent the airways from collapsing. As the airways become smaller and branch into bronchioles, the cartilage diminishes and eventually disappears. The inner lining of the entire keuhkoputkisto is composed of pseudostratified ciliated columnar epithelium, which contains goblet cells that produce mucus. The cilia beat rhythmically to move the mucus, trapping inhaled particles and pathogens, upwards towards the pharynx to be swallowed or expelled. This mucociliary escalator is a crucial defense mechanism for the respiratory system. Inflammation or irritation of the keuhkoputkisto can lead to conditions like bronchitis.