You are taking a lab practical exam,and one station has pins in various internal structures of a bisected mammalian heart.You can orient yourself without picking up and examining the exterior of the heart because
A)the width of the external wall of the right ventricle is thicker than all the other chamber walls.
B)the width of the external wall of the left atrium is thicker than all the other chamber walls.
C)the width of the external wall of the left ventricle is thicker than all the other chamber walls.
D)the width of the external wall of the right atrium is thicker than all the other chamber walls.
E)the ascending aorta exits from the right ventricle.

Question

Quizplus · Accepted Answer

The width of the external wall of the left ventricle is thicker than all the other chamber walls. This is because the left ventricle is responsible for pumping oxygenated blood to the rest of the body and therefore needs to generate a strong force. The right ventricle only needs to pump blood to the lungs, so its wall is thinner. The left atrium receives oxygenated blood from the lungs, but it only needs to pass it on to the left ventricle, so its wall is also thinner. The right atrium receives deoxygenated blood from the body and only needs to pump it to the right ventricle, so its wall is the thinnest of all. The ascending aorta exits from the left ventricle, not the right ventricle.

You Are Taking a Lab Practical Exam,and One Station Has