Final answer:
The cardiac cycles pump blood throughout the body through a complete circulatory circuit, with 'D. circulation' being the correct answer. The systemic, pulmonary, and coronary circuits are all part of the greater circulatory system facilitated by the heart's systolic and diastolic phases.
Step-by-step explanation:
The cardiac cycles continuously pump blood throughout the body through a complete circulatory circuit. The correct answer is D. circulation.
The human circulatory system is crucial for sustaining life by ensuring the transportation of nutrients, gases (like oxygen and carbon dioxide), and wastes in the body. It consists of the heart, blood, and a vast network of vessels that include arteries, veins, and capillaries. The systemic circuit is the part of the circulatory system that transports oxygenated blood from the heart to the body's tissues and returns deoxygenated blood back to the heart. This circuit works together with the pulmonary circuit, which is responsible for oxygenating the blood via the lungs, and the coronary circuit, that supplies the heart tissue with blood. During the cardiac cycle, the heart goes through systole (contraction) and diastole (relaxation), ensuring that blood is efficiently pumped throughout these circuits.