Microradiography of the rabbit's hepatic microcirculation. The similarity of the hepatic portal and pulmonary arterial circulations

Abstract

Abstract Examination of microradiographs of liver indicate that the hepatic arteries supply the richly anastomosing arterial plexus around the biliary ducts. This arterial plexus supplies the portal veins directly and the peripheral hepatic sinusoids. Arterial “boosters” penetrating deep within the lobule were not seen. Hepatic veins receive sinusoids at irregular angles and frequent intervals, whereas portal veins distribute flow through short right angle inlet venules spaced at greater intervals. Pulmonary arteries also distribute flow to capillaries through short right angle precapillaries and pulmonary veins receive capillary drainage at irregular angles and frequent intervals. The location of capillary beds of both liver and lung only 10 to 30 μ from inflow channels appears “ideally” suited for circulations of low vascular resistance. The analogy of liver and lung relates biliary system to airway, hepatic artery to bronchial artery, portal vein to pulmonary artery, hepatic vein to pulmonary vein and ductus venosus to ductus arteriosus. In particular, should the pulmonary artery be considered a “pulmonary portal vein”.