Kaplan Nursing Entrance Practice Exam

What is the primary function of the cardiac cycle?

1. To supply blood to the lungs

2. To facilitate the rhythmic contraction of the heart chambers

3. To transmit sensory signals to the brain

4. To produce electrical impulses for breathing

The correct answer is: To facilitate the rhythmic contraction of the heart chambers

The primary function of the cardiac cycle is indeed to facilitate the rhythmic contraction of the heart chambers. This process is essential for maintaining effective circulation throughout the body. The cardiac cycle consists of two main phases: diastole, during which the heart chambers relax and fill with blood, and systole, where the heart chambers contract to pump the blood out of the heart. This rhythmic contraction ensures that oxygenated blood is distributed to the tissues and organs, while also allowing for the return of deoxygenated blood to the heart. The coordination of these contractions is vital for maintaining adequate blood pressure and ensuring that blood flows in the correct direction through the heart. It plays a crucial role in ensuring that all parts of the body receive the oxygen and nutrients they need to function properly. In contrast, the other options do not accurately reflect the primary function of the cardiac cycle. Supplying blood to the lungs is part of the overall circulatory process, specifically handled by the right side of the heart and the pulmonary circulation, rather than a direct function of the cardiac cycle itself. Transmitting sensory signals to the brain relates more to the nervous system, while producing electrical impulses is primarily related to the pace-setting role of the sinoatrial node in initiating heartbeats rather than