Final answer:
The mechanical activity of the cardiac cycle involves contraction (systole) and relaxation (diastole), kicking off with atrial systole, followed by ventricular systole and ending with ventricular diastole, effectively circulating blood through the body.
Step-by-step explanation:
The mechanical activity of the cardiac cycle is directly linked to the electrical activity of the heart. During the cardiac cycle, the heart goes through a sequence of events that involve contraction (systole) and relaxation (diastole) which result in the pumping of blood through the heart and to the rest of the body. The cycle begins with atrial systole, where the atria contract to push blood into the ventricles. This is followed by atrial diastole and ventricular systole, where the ventricles contract to propel blood into the aorta and pulmonary artery. Finally, the ventricles relax during ventricular diastole, and the heart fills with blood, completing the cycle.
The mechanical activity of the cardiac cycle refers to the events that occur during each heartbeat, involving the contraction and relaxation of the heart muscle. The cardiac cycle consists of two main phases: diastole and systole. During diastole, the heart relaxes and fills with blood. In systole, the heart contracts to pump blood to the rest of the body. This process is coordinated by electrical signals generated by the heart's pacemaker, the sinoatrial (SA) node.