Blood pressure is only ever cardiac output × vascular resistance — so every antihypertensive has to reach in and grab one of them, or drain the volume that feeds the first. Tap a class to watch it cut the circuit; tap the heart, arterioles, kidney, or RAAS to see who works there.
The pressure circuit
Cardiac output
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Vascular resistance
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Blood volume
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Grey line = the untreated patient. Bars show the typical direction and relative size of each effect, not a measured value.