Figure 18-2
-What occurs at the circled label "4" on the graph?
A)peak systolic pressure
B)isovolumetric diastole
C)isovolumetric contraction
D)ventricular refilling
E)increased heart rate

Question

Figure 18-2
-What occurs at the circled label "4" on the graph?
A)peak systolic pressure 
B)isovolumetric diastole 
C)isovolumetric contraction 
D)ventricular refilling 
E)increased heart rate

Quizplus · Accepted Answer

Label "4" on the graph represents the isovolumetric contraction phase, which occurs when the ventricles contract and build pressure, but the aortic valve has not yet opened to eject blood into the aorta. This phase allows for the ventricles to build up enough pressure to overcome the resistance of the aortic valve, which will then open and allow blood to be ejected during systole.

Figure 18-2 -What Occurs at the Circled Label "4" on the Graph