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So I got a Kaplan question saying that Ach administration INCREASES heart rate?
I now get the mechanism they're going for. Ach --> peripheral vasodilation --> reflex tachycardia.
But...like...what about the M2 muscarinic receptor on the heart?? Wouldn't Ach directly cause bradycardia by acting on that receptor? Like, I'm having a hard time imagining that the reflex would win out over the direct stimulation. Can anyone speak to this? In general, is there a good system for determining whether reflex or direct effect wins? Thanks
I now get the mechanism they're going for. Ach --> peripheral vasodilation --> reflex tachycardia.
But...like...what about the M2 muscarinic receptor on the heart?? Wouldn't Ach directly cause bradycardia by acting on that receptor? Like, I'm having a hard time imagining that the reflex would win out over the direct stimulation. Can anyone speak to this? In general, is there a good system for determining whether reflex or direct effect wins? Thanks