intra-acinar arteriole

An intra-acinar arteriole is a small blood vessel that branches from a pulmonary arteriole and carries deoxygenated blood into the pulmonary capillaries surrounding the alveoli of the lungs. These arterioles are part of the pulmonary microvascular network within the lung acinus.

Intra-acinar arterioles are located within the lung acini — the functional units of the lung composed of the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. They are distributed throughout the lung parenchyma alongside the airways and alveoli they supply.

The intra-acinar arteriole delivers deoxygenated blood from the pulmonary circulation to the alveolar capillary network, where gas exchange occurs. Oxygen diffuses into the blood from the alveolar air, and carbon dioxide diffuses in the opposite direction, enabling blood oxygenation.

Structural and functional changes in intra-acinar arterioles may be associated with various pulmonary conditions affecting the pulmonary microvasculature. Research in respiratory medicine has examined these vessels in the context of pulmonary diseases. Any specific concern requires clinical evaluation.

Intra-acinar arterioles are studied primarily through histological examination of lung tissue obtained by biopsy or at autopsy. They are below the resolution of standard clinical imaging but can be examined with micro-CT in research settings. Pulmonary function tests and imaging assess the broader lung parenchyma.