Abstract
The distensibility of the low pressure capacity vessels of the hand was measured in normal subjects while they performed Valsalva''s maneuver. A marked decrease in distensibility occurred about 10 seconds after the onset of Valsalva''s maneuver and persisted for a variable time after straining ceased It is suggested that the fall in distensibility of the systemic low pressure capacity vessels is in part responsible for the characteristic "overshoot" of the arterial blood pressure found when straining ceases.