Cardiovascular System Exam

Correct Answer: A

Rationale: The correct answer is A: Right atrium. The right atrium is the heart chamber that receives deoxygenated blood returning from the body via the superior and inferior vena cava. The blood enters the right atrium from the vena cava and then passes through the tricuspid valve into the right ventricle. Choices B, C, and D are incorrect because the left atrium receives oxygenated blood from the lungs, the right ventricle pumps blood to the lungs for oxygenation, and the left ventricle pumps oxygenated blood to the body.

Correct Answer: A

Rationale: The correct answer is A: Muscle pain. Muscle pain can be a sign of rhabdomyolysis, a serious side effect of statins like atorvastatin. Rhabdomyolysis is a condition where muscle fibers break down rapidly and release their contents into the bloodstream, which can lead to kidney damage. Headache, nausea, and dizziness are not commonly associated with atorvastatin use and are less likely to indicate a serious adverse reaction compared to muscle pain.

Correct Answer: A

Rationale: Atherosclerosis is the correct answer. It is a condition characterized by the hardening and narrowing of arteries supplying blood to the heart due to plaque buildup. This condition increases the risk of heart attacks. Choice B, aneurysm, refers to a balloon-like bulge in an artery, not the hardening and narrowing of arteries. Choice C, arrhythmia, is an irregular heartbeat and not related to arterial hardening. Choice D, peripheral artery disease, involves the narrowing of arteries that supply blood to the limbs, not specifically to the heart.

Correct Answer: A

Rationale: The PR interval measures the time it takes for the electrical impulse to travel from the atria to the ventricles. It is crucial in diagnosing heart rhythm disorders, as abnormalities in this interval can indicate conduction abnormalities between the atria and ventricles. Choices B, C, and D are incorrect. The QRS complex represents ventricular depolarization, the QT interval represents the duration of ventricular repolarization, and the ST segment represents the time between ventricular depolarization and repolarization.

Correct Answer: B

Rationale: The correct answer is B: Atrioventricular Valves. The atrioventricular (AV) valves, including the mitral valve and tricuspid valve, close during ventricular systole to prevent backflow of blood from the ventricles into the atria. They open during ventricular diastole to allow blood flow from the atria into the ventricles. Semilunar valves, choice A, are located at the exits of the ventricles and prevent backflow into the ventricles. The mitral valve and tricuspid valve, choices C and D, are specific types of AV valves.