Figure 3.

Flow tracings from the renal portal vein of Bufo marinus showing sharp extra pulsations at: A) 50 min post injection, flow values shown for renal portal vein; and B) 55 min post injection with recording expanded, flow values shown for pulsations above resting renal portal flow. The injection was performed at t = 0 min. Chart speeds are: A) 1 mm sec^-1; and B) 10 min sec^-1.