An astronaut experiences prolonged spaceflight, which decreases hydrostatic pressure gradients in the cardiovascular system. Which mechanism explains why orthostatic hypotension is likely upon returning to Earth?

💡 Explanation

Reduced baroreceptor sensitivity explains orthostatic hypotension because prolonged reduced hydrostatic pressure in space causes the baroreceptors to downregulate their sensitivity to pressure changes; therefore, upon return to Earth, these receptors are less responsive, rather than responding adequately to postural changes.

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