An elderly man with high blood pressure is prescribed a medication that lowers blood pressure. Which of the foll Would be the mechanism of the drug? activates beta-1 receptors activates beta-2 receptors activates beta-3 receptors inhibits alpha-1 receptors inhibits alpha 2 receptors
An elderly man with high blood pressure is prescribed a medication that lowers blood pressure. Which of the foll Would be the mechanism of the drug?
activates beta-1 receptors
activates beta-2 receptors
activates beta-3 receptors
inhibits alpha-1 receptors
inhibits alpha 2 receptors
Hypertension, also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated.
Targeted activation of the beta-1 receptor in the heart increases sinoatrial (SA) nodal, atrioventricular (AV) nodal, and ventricular muscular firing, thus increasing heart rate and contractility. With these two increased values, the stroke volume and cardiac output will also increase. Thus blood pressure will also increase. Hence the first option is incorrect.
Activation of beta-2 receptors by sympathetic nervous system transmission or drugs will result in vasoconstriction and an increase in peripheral resistance and systemic arterial blood pressure. Hence the second option is incorrect.
Activation of beta-3 receptors by sympathetic nervous system transmission or drugs will result in vasoconstriction and an increase in peripheral resistance and systemic arterial blood pressure. Hence the third option is incorrect.
Alpha-1 blocker lowers the blood pressure by blocking alpha-1 receptors so norepinephrine cannot bind the receptor, causing the blood vessels to dilate. Without the resistance in the blood vessels the blood runs more freely. Hence the fourth option is correct.
Alpha 2 receptors in the brain stem and in the periphery inhibit sympathetic activity and thus lower blood pressure. Thus alpha-2 inhibition would cause an increase in blood pressure. Hence the fifth option is incorrect.
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