Fig. 8

The percent change in average cross-sectional vessel area during the cardiac cycle in the dependent compared to the non-dependent position. The dark grey bars represent the percent change in the pulmonary arterial areas for the right and left lung, respectively. The chequered bars represent the percent change in the sum of the areas for the superior and inferior veins in the right and left lung, respectively. The venous cross-sectional area increased in the dependent position compared to when the same lung was in the non-dependent position. The arterial area remained unchanged with body position. The P-values reflect the hypothesis that bars have a non-zero value, i.e. that vessel cross sectional area is affected when a lung goes from being dependent in the lateral position to being non-dependent in the contralateral position