Which of the following are considered events of the cardiac cycle?

• A. Inhalation, exhalation, and gas exchange
• B. Atrial systole, ventricular systole, and diastole
• C. Depolarization, repolarization, and hyperpolarization
• D. Filtration, reabsorption, and secretion

Answer: (B)

Verified step by step guidance

1. Understand the cardiac cycle: The cardiac cycle refers to the sequence of events that occur in the heart during one heartbeat, including the contraction and relaxation of the atria and ventricles.
2. Identify the phases of the cardiac cycle: The main phases are atrial systole, ventricular systole, and diastole. Atrial systole is the contraction of the atria, ventricular systole is the contraction of the ventricles, and diastole is the relaxation phase where the heart fills with blood.
3. Differentiate between the options: Inhalation, exhalation, and gas exchange are related to the respiratory system, not the cardiac cycle. Depolarization, repolarization, and hyperpolarization are electrical events in neurons and muscle cells, including cardiac muscle, but they are not phases of the cardiac cycle. Filtration, reabsorption, and secretion are processes related to the kidneys and the urinary system.
4. Focus on the correct answer: Atrial systole, ventricular systole, and diastole are the correct events of the cardiac cycle, as they describe the mechanical actions of the heart during a heartbeat.
5. Summarize the cardiac cycle: The cardiac cycle is a coordinated sequence of atrial and ventricular contractions and relaxations that ensure efficient blood flow through the heart and to the rest of the body.