Teaching the effects of gravity and intravascular and alveolar pressures on the distribution of pulmonary blood flow using a classic paper by West et al

Louisiana State University Health Sciences Center, Louisiana State University School of Medicine, New Orleans, Louisiana Address for reprint requests and other correspondence: M. G. Levitzky, Louisiana State Univ. Health Sciences Center, Louisiana State Univ. School of Medicine, 1901 Perdido St., New Orleans, LA 70112-1393 (e-mail: mlevit{at}lsuhsc.edu ) Abstract "Distribution of blood flow in isolated lung; relation to vascular and alveolar pressures" by J. B. West, C. T. Dollery, and A. Naimark ( J Appl Physiol 19: 713–724, 1964) is a classic paper, although it has not yet been included in the Essays on the American Physiological Society Classic Papers Project ( http://www.the-aps.org/publications/classics/ ). This is the paper that originally described the "zones of the lung." The final figure in the paper, which synthesizes the RESULTS and DISCUSSION , is now seen in most textbooks of physiology or respiratory physiology. The paper is also a model of clear, concise writing. The paper and its final figure can be used to teach or review a number of physiological concepts. These include the effects of gravity on pulmonary blood flow and pulmonary vascular resistance; recruitment and distention of pulmonary vessels; the importance of the transmural pressure on the diameter of collapsible distensible vessels; the Starling resistor; the interplay of the pulmonary artery, pulmonary vein, and alveolar pressures; and the vascular waterfall. In addition, the figure can be used to generate discovery learning and discussion of several physiological or pathophysiological effects on pulmonary vascular resistance and the distribution of pulmonary blood flow. Key words: pulmonary blood flow; zones of the lung; Starling resistor; vascular waterfall