Department of Medicine, University of Washington, USA.
Compr Physiol. 2011 Jan;1(1):375-95. doi: 10.1002/cphy.c100002.
With increasing spatial resolution of regional ventilation and perfusion, it has become more apparent that ventilation and blood flow are quite heterogeneous in the lung. A number of mechanisms contribute to this regional variability, including hydrostatic gradients, pleural pressure gradients, lung compressibility, and the geometry of the airway and vascular trees. Despite this marked heterogeneity in both ventilation and perfusion, efficient gas exchange is possible through the close regional matching of the two. Passive mechanisms, such as the shared effect of gravity and the matched branching of vascular and airway trees, create efficient gas exchange through the strong correlation between ventilation and perfusion. Active mechanisms that match local ventilation and perfusion play little if no role in the normal healthy lung but are important under pathologic conditions.
随着区域通气和灌注的空间分辨率不断提高，人们越来越清楚地认识到，肺内通气和血流存在明显的不均一性。许多机制导致了这种区域性变异性，包括静压梯度、胸膜压力梯度、肺顺应性以及气道和血管树的几何形状。尽管通气和灌注存在明显的异质性，但通过两者的密切区域匹配，可以实现有效的气体交换。被动机制，如重力的共同作用和血管与气道树的匹配分支，通过通气和灌注之间的强相关性，创造了有效的气体交换。在正常健康的肺中，匹配局部通气和灌注的主动机制几乎不起作用，但在病理条件下则非常重要。
