ATI RN
100 Questions on the Cardiovascular System Questions
Question 1 of 5
For blood clotting to occur normally:
Correct Answer: D
Rationale: Vitamin K is essential for the liver to synthesize clotting factors (e.g., II, VII, IX, X). Heparin inactivation aids but isn’t required, vitamin C is unrelated, and tissue damage triggers extrinsic clotting but isn’t always necessary.
Question 2 of 5
The ventricular muscles accept impulses directly from
Correct Answer: D
Rationale: The Purkinje fibers deliver impulses directly to ventricular myocardium, causing rapid, coordinated contraction. The AV node delays the signal, the Bundle of His splits it, and bundle branches distribute it, but Purkinje fibers are the final step to the muscle.
Question 3 of 5
Vascular resistance is determined by:
Correct Answer: D
Rationale: Vascular resistance is primarily determined by vessel diameter (D), as per Poiseuille’s law (resistance ∝ 1/r⁴), where small changes in radius greatly affect resistance. Length (A) and viscosity (B) contribute but are less dynamic, C is vague, and E (blood pressure) is an outcome, not a determinant.
Question 4 of 5
Identify the vessel(s) that return blood to the left atrium.
Correct Answer: D
Rationale: The left atrium receives oxygenated blood from the lungs via the right and left pulmonary veins (D). The coronary sinus (A, B) drains to the right atrium, and the pulmonary trunk (C) is an artery from the right ventricle.
Question 5 of 5
Which of the following is NOT true of atherosclerosis?
Correct Answer: D
Rationale: Atherosclerosis is caused by endothelial injury (D is false), leading to plaque formation. Smoking (A), insulin-dependent diabetes mellitus (C), and possibly H. pylori (B, via inflammation) are risk factors.