During the standard cardiac cycle,blood passes through four different valves.Some newborns suffer from a structural defect that forms an open passage between the atria;what valves would be bypassed in this condition?
A) the left atrium/ventricle valve and the right ventricle/artery valve
B) the left atrium/ventricle valve and the left ventricle/artery valve
C) the right atrium/ventricle valve and the right ventricle/artery valve
D) the right atrium/ventricle valve and the left ventricle/artery valve

Question

Quizplus · Accepted Answer

The defect described in the question is known as atrial septal defect (ASD), which causes an opening between the two atria of the heart. In a normal cardiac cycle, blood flows from the right atrium to the right ventricle through the tricuspid valve, and then from the right ventricle to the pulmonary artery through the pulmonary valve. If there is an ASD, blood can flow from the left atrium to the right atrium, and then to the right ventricle, bypassing the tricuspid valve. But blood still flows through the pulmonary valve to the pulmonary artery, so the left ventricle/artery valve is not affected. Therefore, the correct answer is C) the right atrium/ventricle valve and the right ventricle/artery valve.

During the Standard Cardiac Cycle,blood Passes Through Four Different Valves