Beginning with all chambers of the heart in the "relaxed" phase, describe the cardiac cycle in mammals, with systole and diastole of the atria and ventricles. For each time point in the cycle you select, state the following:. A) Whether the atria and ventricles are contracting or relaxing
B) Whether the AV valves and semilunar valves are closed or open
C) Whether the pressure in the atria and ventricles is high or low.

Answer and Explanation:

The cardiac cycle throughout mammals consists of four main different steps of activity:

Isovolumic relaxation: During which the AV valve is locked, the Semi-Lunar valves are closed. One such stage consists of a ventricular contraction.Inflow Stage: And the same for atrial systole, and during that blood going back to the heart circulates via the atria to comfortable ventricles (left or right). AV valve remains located as well as the semi-lunar valve does seem to be inaccessible. The whole stage is known as the ventricular filling venue.Isovolumic contraction: Both the AV valve as well as the Semi-lunar valve remain sealed or disabled. AV Valve decides to close at either the final moment including its ventricular, this same blood circulation slows down the ventricle from contracting.Ventricular Ejection stage: This valve seems to be closed as well as the Semi-lunar valve is accessible. Ventricles or even blood need to circulates from the heart and lungs to the tissues as well as to the surrounding tissue or human body.