Question

question
which of the following statements regarding the cardiac cycle is false?
answer
all of the listed statements are true; none is false.
blood will flow out of an atrium only as long as the atrioventricular valve is open, and atrial pressure exceeds ventricular pressure.
the atrioventricular and semilunar valves help ensure a one - way flow of blood, despite pressure oscillations.
blood will flow from a ventricle into the aorta or pulmonary trunk only as long as the semilunar valve is open, and arterial pressure exceeds ventricular pressure.

Explanation:

• For blood to flow from a ventricle into the aorta or pulmonary trunk, ventricular pressure must exceed arterial pressure, not the other way around. When ventricular pressure is higher than arterial pressure, the semilunar valve opens and blood is ejected.
• The statement about blood flowing out of an atrium (atrial pressure > ventricular pressure with atrioventricular valve open) is correct. Atrioventricular and semilunar valves do ensure one - way blood flow.

Answer:

Blood will flow from a ventricle into the aorta or pulmonary trunk only as long as the semilunar valve is open, and arterial pressure exceeds ventricular pressure.