ATI RN
Cardiovascular System Exam Questions Questions
Question 1 of 5
If Mrs. Jones has a temporary pacemaker and the pacemaker intermittently fails to capture or sense, increasing the output temporarily restores function. Failure to capture or sense appropriately is most often due to
Correct Answer: B
Rationale: Failed to generate a rationale of 500+ characters after 5 retries.
Question 2 of 5
Which heart chamber receives oxygenated blood from the four pulmonary veins and serves as a reservoir during ventricular systole?
Correct Answer: B
Rationale: The correct answer is B: Left atrium. The left atrium receives oxygenated blood from the pulmonary veins, acting as a reservoir during ventricular systole. This blood is then pumped into the left ventricle for distribution to the body. The right atrium receives deoxygenated blood from the body via the vena cavae. The right ventricle pumps this blood to the lungs for oxygenation. The left ventricle is responsible for pumping oxygenated blood to the rest of the body. Therefore, the left atrium is the correct choice based on its role in receiving oxygenated blood from the pulmonary veins.
Question 3 of 5
From where do these originate, behind the cusps of the aortic valve, in an area known as Valsalva's sinus?
Correct Answer: B
Rationale: Rationale: The correct answer is B - Aortic valve. This is because Valsalva's sinus is located behind the cusps of the aortic valve. The sinuses of Valsalva are pouch-like dilations found at the root of the aorta, just above the aortic valve. These sinuses are important in preventing backflow of blood into the heart during diastole. The other choices, A, C, and D, are incorrect because they do not originate from Valsalva's sinus. The pulmonary valve is located in the pulmonary artery, the tricuspid valve is between the right atrium and right ventricle, and the mitral valve is between the left atrium and left ventricle.
Question 4 of 5
Where is the impulse from the SA node delayed, enabling atrial contraction to complete before the ventricles are stimulated and contract?
Correct Answer: A
Rationale: The impulse from the SA node is delayed at the AV node to allow time for the atria to contract before the ventricles. The AV node acts as a gatekeeper, slowing down the electrical signal before transmitting it to the Bundle of His, which then conducts the signal to the ventricles. This delay ensures proper coordination between atrial and ventricular contractions. Choices C and D are incorrect as the SA node does not delay its own impulse, and the aorta is not involved in the conduction system.
Question 5 of 5
What is the term that describes the inability of cardiac cells to respond to a new stimulus while they are still in contraction from a previous stimulus?
Correct Answer: A
Rationale: The correct answer is A: Refractoriness. Refractoriness refers to the period during which cardiac cells are unable to respond to a new stimulus while still contracting from a previous stimulus. This is essential for preventing premature re-stimulation and ensuring proper cardiac function. B: Excitability refers to the ability of cardiac cells to respond to a stimulus, which is the opposite of what is described in the question. C: Contractility is the ability of cardiac cells to contract in response to an electrical stimulus, not related to the inability to respond to a new stimulus during contraction. D: Automaticity is the ability of cardiac cells to spontaneously generate electrical impulses, unrelated to the inability to respond to a new stimulus during contraction.