Which of the following describes acidosis effects on peripheral vessels and the heart's responsiveness to catecholamines?

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Multiple Choice

Which of the following describes acidosis effects on peripheral vessels and the heart's responsiveness to catecholamines?

Acidosis alters vascular and cardiac function by making peripheral vessels relax and by dulling the heart’s response to catecholamines. The high hydrogen ion concentration directly promotes vasodilation of peripheral vessels, which lowers systemic vascular resistance. At the same time, the heart becomes less responsive to sympathetic catecholamines, so its ability to increase force of contraction and rate in response to stress is blunted. Because the vessels are dilated and the heart isn’t signaling as robustly to catecholamines, cardiac output tends to drop initially. The body attempts to compensate by increasing sympathetic activity, which raises heart rate (tachycardia) and can help maintain or modestly boost stroke volume when preload and other conditions allow. This combination—vasodilation, reduced catecholamine responsiveness, initial decrease in cardiac output, with compensatory tachycardia and potential increases in stroke volume—fits the described pattern.

Acidosis alters vascular and cardiac function by making peripheral vessels relax and by dulling the heart’s response to catecholamines. The high hydrogen ion concentration directly promotes vasodilation of peripheral vessels, which lowers systemic vascular resistance. At the same time, the heart becomes less responsive to sympathetic catecholamines, so its ability to increase force of contraction and rate in response to stress is blunted.

Because the vessels are dilated and the heart isn’t signaling as robustly to catecholamines, cardiac output tends to drop initially. The body attempts to compensate by increasing sympathetic activity, which raises heart rate (tachycardia) and can help maintain or modestly boost stroke volume when preload and other conditions allow. This combination—vasodilation, reduced catecholamine responsiveness, initial decrease in cardiac output, with compensatory tachycardia and potential increases in stroke volume—fits the described pattern.

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