Each lung has a hilus through which what structures reach the lung?

The hilus of each lung is the point of entry and exit for several vital structures, notably the bronchial tubes and lymphatic vessels. The bronchial tubes are the major airways that branch off from the trachea and lead into the lungs, allowing for the passage of air to and from the alveoli where gas exchange occurs. Lymphatic vessels at the hilus play a crucial role in draining lymph fluid from the lungs, helping to filter out pathogens and maintain fluid balance within the thoracic cavity.

The other options, while involving important components of the lung's anatomy, do not accurately describe the structures that enter and exit through the hilus. Nerves and arteries, while present in the lung tissue, do not primarily pass through the hilus; instead, they traverse along different pathways. Similarly, while veins and capillaries are essential for pulmonary circulation, they are not the primary structures associated with the hilus. Lastly, alveoli and bronchioles are part of the lung's internal structure but do not enter the lung at the hilus; they are the endpoints of the bronchial tree.