Blood Returning to the Mammalian Heart in a Pulmonary Vein

Question

Blood returning to the mammalian heart in a pulmonary vein drains first into the
A) vena cava.
B) left atrium.
C) right atrium.
D) left ventricle.
E) right ventricle.

Accepted Answer

Pulmonary veins carry oxygenated blood from the lungs to the heart, where it enters the left atrium. From there, it passes through the mitral valve and into the left ventricle, which pumps it out to the rest of the body.