Which term accurately represents the relaxation phase of heart muscle?

The relaxation phase of heart muscle is termed diastole. During diastole, the heart muscles relax after contraction, allowing the chambers of the heart (the atria and ventricles) to fill with blood. This phase is essential for proper heart function, as it ensures that there is adequate blood volume in the heart before the next contraction, which is referred to as systole.

In diastole, the pressure within the heart chambers decreases, and the heart is in a state of rest, optimizing blood flow and oxygen delivery to the body. The term accurately describes this critical phase of the cardiac cycle, distinguishing it from other physiological processes.

The other terms listed do not relate to heart muscle relaxation. A dimer refers to a molecular structure consisting of two subunits, differentiation pertains to the process by which cells become specialized, and diabetes is a metabolic disease that primarily affects the regulation of blood sugar levels. Therefore, diastole is the only term relevant to the relaxation phase of heart muscle.