If a patient experiences severe hypotension during anaphylaxis caused by mast cell degranulation, which compensatory mechanism fails to adequately address the histamine-induced vasodilation, leading to circulatory collapse?

💡 Explanation

The baroreceptor reflex attempts to compensate for hypotension through sympathetic activation, increasing heart rate and vasoconstriction. However, in anaphylaxis, massive histamine release causes widespread vasodilation that overwhelms the sympathetic response, because histamine's effects are too potent and diffuse; therefore, blood pressure remains dangerously low, rather than being restored by angiotensin or ADH.

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