The function of the receptors can also be tested by monitoring the changes in pulse and blood pressure that occur in response to brief periods of straining (forced expiration against a closed glottis: the Valsalva maneuver). Valsalva maneuvers Occurs during coughing, defecation, and heavy lifting. Blood pressure rises at the onset of straining because the increase in intrathoracic pressure is added to the pressure of the blood in the aoa. It then falls because the high intrathoracic pressure compresses the veins, Decreasing venous return Decreasing cardiac output. The decrease in aerial pressure and pulse pressure inhibit the baroreceptors, causing : Tachycardia Rise in peripheral resistance.