Journal of Applied Physiology, Vol 52, Issue 4 1035-1042, Copyright © 1982 by American Physiological Society
Functional diagrams of flow and volume for the dog's lung
D. S. Moffatt, A. C. Guyton and T. H. Adair
Quantitative diagrams have been constructed from data obtained in isolated
perfused dog lungs for the multiple interrelationships among pressure,
volume, and flow characteristics of the pulmonary vasculature. These
characteristics are described in the form of functional diagrams for flows
from 0.3 to 1.0 l . min-1 . 100 g wet lung weight-1 (WLW), for venous
pressures from -8 to +14 Torr, and for arterial pressures from 16 to 30
Torr. The quantitative relationships were shown not to change significantly
as the transpulmonary pressure changes within the range from 3 to 10 Torr.
The change in blood volume with arterial pressure, called the "distributed
arterial compliance," averaged 1.5 g . Torr-1 . 100 g WLW-1. This
compliance was nearly constant over the range of arterial pressure studied.
On the other hand, the change in blood volume with venous pressure, called
the "distributed venous compliance" was different for different levels of
venous pressures. Its maximum value was 1.04 g . Torr-1 . 100 g WLW-1 when
the venous pressure was near 2 Torr. At venous pressures both above and
below this pressure level this compliance decreased. These distributed
compliances are described as resulting to a significant extent from changes
in flow patterns through the pulmonary circulation rather than being direct
indications of the true vascular compliances.
