Answer:
Isovolumetric Phase
Explanation:
Heart contraction presents various phases that depend on the volume of blood and pressure present in each chamber. From these variables, one can plot blood volume vs pressure in an x and y axis.
This question describes a phase where all valves are closed and no changes in blood volume is present. This occurs during two parts of the heart cycle called isovolumetric (iso-: same, -volumetric: volume) phase, which can be seen during contraction and relaxation. This phenomen is due to the pressure gradients the ventricle has to overcome to open the valves.
