A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. To travel from the artery to the thumb and then back to the left ventricle, this red blood cell must pass through ________.

Question

Quizplus · Accepted Answer

Arteries carry oxygenated blood away from the heart and deliver it to various parts of the body. When the red blood cell reaches the thumb, it has to pass through one capillary bed in order to deliver oxygen to the thumb's cell. After delivering oxygen, the cell will enter a venule and travel through veins to return to the heart. On its journey back to the heart, the red blood cell will have to pass through a second capillary bed in order to exchange carbon dioxide for oxygen. Therefore, the red blood cell must pass through two capillary beds in order to complete its journey from the artery to the thumb and back to the left ventricle.

A Human Red Blood Cell in an Artery of the Left