What prevents oxygen-rich blood from mixing with oxygen-poor blood in the heart?
A)The tricuspid valve
B)The fibrous pericardium
C)The aortic and pulmonary semilunar valves
D)The interatrial and interventricular septa
E)The intercalated discs

Question

Quizplus · Accepted Answer

The interatrial and interventricular septa are walls that separate the atria and ventricles, respectively. Oxygen-rich blood enters the left atrium and is pumped through the mitral valve into the left ventricle, while oxygen-poor blood enters the right atrium and is pumped through the tricuspid valve into the right ventricle. The interventricular septum prevents the oxygen-rich blood in the left ventricle from mixing with the oxygen-poor blood in the right ventricle. Similarly, the interatrial septum prevents oxygen-rich blood in the left atrium from mixing with oxygen-poor blood in the right atrium. Thus, the correct choice is D.

What Prevents Oxygen-Rich Blood from Mixing with Oxygen-Poor Blood in the Heart