ATI RN
Cardiovascular System Practice Exam Questions
Question 1 of 5
In third-degree atrioventricular block, all sinus impulses fail to activate the ventricles. This will be detected by
Correct Answer: C
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 2 of 5
Identify the three layers of the heart:
Correct Answer: A
Rationale: Rationale: 1. Endocardium: Innermost layer lining the heart chambers. 2. Myocardium: Middle layer composed of cardiac muscle tissue. 3. Epicardium: Outermost layer forming the visceral pericardium. Therefore, the correct answer is A. Summary: B is incorrect as it includes Pericardium instead of Myocardium. C is incorrect as it switches the positions of Myocardium and Epicardium. D is incorrect as it has the layers listed in the wrong order and includes Pericardium as the innermost layer.
Question 3 of 5
Which valve opens during ventricular systole and closes during ventricular diastole?
Correct Answer: B
Rationale: During ventricular systole, the ventricles contract to pump blood out. The pulmonary valve opens to allow blood to be ejected from the right ventricle into the pulmonary artery, leading to the lungs. This prevents the backflow of blood into the right ventricle during ventricular diastole when the ventricles relax. The aortic valve opens during ventricular systole to allow blood to be ejected from the left ventricle into the aorta, not during ventricular diastole. The mitral valve and tricuspid valve control the flow of blood between the atria and ventricles, not during ventricular systole. Therefore, the correct answer is B (Pulmonary valve).
Question 4 of 5
During which process does coronary artery blood flow to the myocardium occur during diastole, when coronary vascular resistance is reduced?
Correct Answer: A
Rationale: The correct answer is A: Coronary perfusion pressure. Coronary perfusion pressure is the pressure gradient that drives blood flow through the coronary arteries into the myocardium during diastole when the coronary vascular resistance is reduced. This pressure gradient is essential for delivering oxygen and nutrients to the heart muscle when it is relaxed and filling with blood. During diastole, the coronary arteries receive blood flow predominantly due to the pressure difference between the aortic diastolic pressure and the pressure in the coronary vasculature. Summary of why the other choices are incorrect: B: Coronary vascular resistance - This factor is reduced during diastole, allowing for increased blood flow, but it does not directly drive blood flow to the myocardium. C: Diastolic filling - This refers to the filling of blood into the ventricles of the heart, not specifically the flow of blood through the coronary arteries. D: Ventricular ejection - This occurs during systole when the ventricles contract
Question 5 of 5
What is the ability of cardiac cells to respond to an impulse by transmitting the impulse along cell membranes?
Correct Answer: C
Rationale: The correct answer is C: Conductivity. Cardiac cells have the ability to transmit impulses along cell membranes, allowing for the coordinated contraction of the heart. Conductivity refers to this specific property of cardiac cells to propagate electrical signals. Contractility (A) refers to the ability of cardiac muscle cells to generate force during contraction. Automaticity (B) refers to the ability of cardiac cells to spontaneously generate electrical impulses. Rhythmicity (D) refers to the regularity of these electrical impulses in the heart. Conductivity is the most relevant choice as it directly addresses the transmission of impulses along cell membranes in cardiac cells.