Flow rate of erythrocytes in the capillaries of the lung

The rate of blood flow in the capillaries of the rabbit lung was investigated by cinematographic methods and found to be 0.75 mm/sec during artificial respiration with air applied with a Starling pump during the filming. Using our measured value for the average capillary length of 68 μ, the average contact time for the erythrocytes is 0.1 sec. If we assume the capillaries to have a length of 100 μ, the contact time would amount to 0.15 ± 0.05 sec. The discrepancy with the saturation time obtained from in vitro experiments is discussed. It is shown that insufflation increases the capillary blood flow in the lungs. blood flow; velocity; rabbit; microcinematography Submitted on February 24, 1964