Under quiet conditions, blood returning to the heart retains about _______of its oxygen content when it leaves the lungs.
A) 25 percent
B) 90 percent
C) 50 percent
D) 100 percent
E) 75 percent

Question

Quizplus · Accepted Answer

Under quiet conditions, blood returning to the heart retains about 75 percent of its oxygen content when it leaves the lungs, as the body does not require all the oxygen carried by the blood at rest.

Under Quiet Conditions, Blood Returning to the Heart Retains About