[The distribution of blood flow velocity in the terminal bed of the rat mesentery].

Blood flow velocities in microvessels of the rat intestinal mesentery were determined by means of prism-grating method. Mean velocity values in arterioles were 1.9 +/- 0.1, in venules 1.2 +/- 0.2, in capillaries 0.82 +/- 0.06 and in arteriole-venule anastomoses 1.7 +/- 0.2 mm/s. These values do not vary significantly in arterioles with internal diameter from 23.2 to 6.9 mm and in venules from 7.2 to 28.2 mm. The most significant velocity changes appear in the passage of arterioles into capillaries (50%) and between capillaries and venules (40%).