The Response of the Ureter and Pelvis to Changing Urine Flows

Abstract

The response of the ureter of the dog to changing urine flow was investigated in trained unanesthetized dogs by direct observation of peristaltic activity and graphic recording of peristaltic waves. Changes in pelvic pressure during variations in urine flow were also studied. During increasing urine flow, the vigor of ureteral peristaltic contractions increases but the frequency of peristalsis remains constant, except during marked diuresis when the frequency decreases. The pressure within the renal pelvis also increases with urine flow, except during extreme osmotic diuresis, where it reaches a fixed upper limit despite further increases in flow. At this diuretic stage, the ureters behave as simple dilated tubes allowing urine to pour out in a continuous stream.