What should be the condition of the atria during mid-diastole?

During mid-diastole, the atria should be in a relaxed state. This relaxation is crucial as it allows the atria to fill with blood returning from the venous circulation. The mid-diastolic phase follows the rapid filling phase of the atria and is characterized by a decrease in atrial pressure, enabling passive filling from the pulmonary veins and the superior and inferior vena cavae.

As the heart transitions through the cardiac cycle, during mid-diastole the ventricles are also in a relaxed state, allowing for the appropriate hemodynamic conditions for blood to move into the ventricles from the atria when the atrioventricular valves are open. The relaxation of the atria is essential for optimal filling of the heart, which is critical for maintaining an effective cardiac output.

In summary, the correct condition of the atria during mid-diastole is relaxed, facilitating the passive filling of the chambers with blood.