Final answer:
Pulmonary circulation provides nourishment specifically to the bronchial tree of the lower respiratory system, via the bronchial arteries, ensuring a rich supply of oxygenated blood to support the airways.
Step-by-step explanation:
Pulmonary circulation specifically nourishes the bronchial tree, which is a part of the lower respiratory system. The bronchial arteries, which are systemic branches from the aorta, provide oxygenated blood to the lungs in addition to the blood received from the pulmonary circuit. Within the lungs, air passes through the trachea and enters into the two primary bronchi.
These bronchi branch out into secondary and tertiary bronchi, and eventually form smaller bronchioles that spread throughout the lung. The bronchi and bronchioles are supported by cartilage and smooth muscle, which are innervated by both the parasympathetic and sympathetic nervous systems. The respiratory bronchioles end in alveolar ducts and sacs where gas exchange occurs, and they are surrounded by a network of pulmonary capillaries interconnected with the circulation system.