Solved UPSC CDS/OTA Question
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Q · Circulatory Systemmedium · 45s
Which hormone increases heart rate and contractility?
TopicCirculatory System
Question Typemultiple choice
Difficultymedium
Marking+1 / −0.33
Test Duration30 min
Step-by-Step Solution
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Norepinephrine, released by sympathetic nerves and adrenal medulla, binds β₁-adrenergic receptors in the heart, increasing SA node firing rate and cardiomyocyte contractility (positive chronotropic and inotropic effects).
Final Answer: Option B - Norepinephrine