Show up ready on day 1 with a complete understanding of the core topics needed for a successful journey through PA school.
Patient care begins with knowledge, and knowledge begins with the fundamentals. The Pre-PA Prep Qbank Bundle covers these fundamentals with anatomy, physiology, medical terminology, PA professional practice, and wellness.
During which phases of the cardiac cycle are all the valves closed?
The cardiac cycle consists of seven phases that lead to blood being circulated throughout the body. The phases of the cardiac cycle are atrial systole, isovolumetric ventricular contraction, rapid ventricular ejection, reduced ventricular ejection, isovolumetric ventricular relaxation, rapid ventricular filling, and reduced ventricular filling. The isovolumetric ventricular contraction phase is marked by an increase in ventricular pressure as the ventricles contract. This phase begins when the atrioventricular (tricuspid and mitral) valves close due to the pressure in the ventricles exceeding the pressure in the atria. The volume of the blood in the ventricles remains constant during isovolumetric ventricular contraction because the atrioventricular and semilunar valves (aortic and pulmonic) are closed. Isovolumetric ventricular relaxation occurs between ventricular ejection of blood and ventricular filling. It begins when the semilunar valves close following ventricular contraction and ends with the opening of the atrioventricular valves. The volume of blood in the ventricles remains constant because each of the valves is closed, and the pressure decreases because the ventricles are relaxed.
Atrial systole and isovolumetric ventricular contraction (A) is incorrect because, during atrial systole, the atrioventricular valves are open, as blood is flowing into the ventricles. Rapid ventricular filling and reduced ventricular filling (C) are phases of the cardiac cycle where the atrioventricular valves are open and the semilunar valves are closed. Reduced ventricular ejection and isovolumetric ventricular relaxation (D) is incorrect because the semilunar valves are open during reduced ventricular ejection.
Understanding why an answer choice is incorrect is just as important as knowing why one is correct. That’s why every Rosh Review question includes detailed explanations for the correct and incorrect answer choices. These comprehensive summaries link the most important components of a topic—from risk factors to diagnostics and treatment—giving you the context to build relationships between them.
Custom illustrations and tables help further clarify the core concepts. When information is presented visually, you can focus on meaning, easily reorganize and group similar ideas, and make better use of your memory.
Your personal analytics allow you to see your progress at all times, so you can create an efficient and effective learning strategy and stay on pace with your plan.
Deep insights to determine your strengths and weaknesses so you can spend your time on the subjects that matter.
Discover how your answer choices align with those selected by learners across the country.
Using data generated by previous users, your Qbank gives a prediction of how likely you are to pass your exam.
After each explanation is a straightforward question with a simple, memorizable answer that reinforces the corresponding topic.
Q: In which part of the electrocardiogram does isovolumetric ventricular contraction begin?
Reveal AnswerA: QRS complex, which represents the electrical activation of the ventricles.