Bronkierne

Bronkierne are the two main air passages that branch from the trachea and conduct air into the lungs. They form the central part of the bronchial tree and give rise to progressively smaller airways, including lobar and segmental bronchi, until the airflow reaches the bronchioles. The term bronkierne is used in Danish to refer to these structures.

Anatomy and branching patterns show regional differences. The right main bronchus is shorter, wider, and more vertical than the left, and it divides into three lobar bronchi (for the three lobes of the right lung). The left main bronchus is longer and narrower, dividing into two lobar bronchi for the two lobes on that side. Each lobar bronchus further divides into segmental (tertiary) bronchi, which supply specific lung segments. The cartilaginous support of the bronchi is most prominent in the larger sections and diminishes toward the smaller bronchi, where smooth muscle becomes increasingly important and mucus-secreting glands are present.

Functionally, bronkierne serve as the conducting airways, warming and humidifying inspired air and filtering particles. The mucosa is lined with ciliated, mucus-secreting epithelium that helps remove debris via the mucociliary escalator. Autonomic innervation regulates diameter: sympathetic activity tends to dilate airways, while parasympathetic activity via the vagus nerve promotes constriction. Blood supply to the bronchi includes bronchial arteries that nourish the airway walls, with venous drainage and lymphatic networks draining to regional nodes.

Clinical relevance includes acute or chronic bronchitis, asthma, chronic obstructive pulmonary disease, and bronchiectasis. Procedures such as bronchoscopy target the bronchial tree for diagnosis or treatment, and the anatomy of the bronkierne influences risk of foreign body aspiration and patterns of disease.