Figure 18-2
-What occurs at the area labeled "D" on the graph?
A)AV valves open
B)semilunar valves open
C)diastolic refilling begins
D)both AV valves open and diastolic refilling begins
E)both semilunar valves open and diastolic refilling begins

Question

Figure 18-2
-What occurs at the area labeled "D" on the graph?
A)AV valves open 
B)semilunar valves open 
C)diastolic refilling begins 
D)both AV valves open and diastolic refilling begins 
E)both semilunar valves open and diastolic refilling begins

Quizplus · Accepted Answer

Area labeled "D" represents the beginning of ventricular diastole, which is the relaxation phase of the cardiac cycle. During this phase, the pressure in the ventricles decreases and the AV valves open, allowing blood to flow from the atria into the ventricles. Therefore, both AV valves open and diastolic refilling begins at this point on the graph. The semilunar valves remain closed during this phase.

Figure 18-2 -What Occurs at the Area Labeled "D" on the Graph