Endocrine physiology: Identify the primary cardiovascular effect increased by norepinephrine (noradrenaline). Full question: Norepinephrine increases which parameter most prominently via α₁-mediated vasoconstriction? Choose the correct option.
General Knowledge
Biology
Difficulty: Easy
Choose an option
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ABlood pressure (via increased peripheral vascular resistance)
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BDigestive activity and gut motility
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CUrine output by direct renal filtration effect
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DBody temperature through sweating
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EOnly heart rate with no change in vessels
Answer
Correct Answer: Blood pressure (via increased peripheral vascular resistance)
Explanation
Given data
- Hormone/neurotransmitter: Norepinephrine.
Concept / ApproachNorepinephrine predominantly stimulates α₁-adrenergic receptors in vascular smooth muscle → vasoconstriction → ↑ total peripheral resistance → ↑ blood pressure. It can also increase heart rate via β₁, but baroreflex may blunt HR; the hallmark effect is raised BP.
Eliminating distractorsParasympathetic tone increases GI motility, not NE. NE does not directly increase GFR/urine output; intense vasoconstriction can reduce renal flow. Thermoregulation and pure HR-only effects are not the primary signature.
Final AnswerBlood pressure (via increased peripheral vascular resistance).