Cardiovascular System Exam

Correct Answer: A

Rationale: The correct answer is A: Platelet count. When administering enoxaparin (Lovenox) for DVT prophylaxis, it is crucial to monitor the platelet count as enoxaparin can lead to thrombocytopenia, a decrease in platelet levels. Monitoring the platelet count helps in early detection of this potential adverse effect. Choices B, C, and D are incorrect because PT/INR, aPTT, and hemoglobin levels are not the most important lab values to monitor specifically for enoxaparin administration and DVT prophylaxis.

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.

Correct Answer: A

Rationale: The correct answer is A, Coronary artery bypass graft (CABG). This surgical procedure involves grafting a blood vessel to bypass a blocked coronary artery, improving blood flow to the heart muscle. Choice B, Valve replacement, is a procedure to replace a damaged heart valve and is not directly related to bypassing blocked arteries. Choice C, Stent placement, involves inserting a mesh tube to keep blocked arteries open and is different from grafting a blood vessel. Choice D, Angioplasty, is a procedure to widen narrowed or blocked arteries, typically using a balloon catheter, and does not involve grafting a blood vessel.

Correct Answer: A

Rationale: The correct answer is the SA node. The sinoatrial (SA) node is known as the natural pacemaker of the heart as it generates electrical impulses initiating each heartbeat. The SA node is located in the right atrium and sets the rhythm and rate of the heartbeat. The AV node (choice B) is responsible for delaying the electrical impulse to allow the atria to contract before the ventricles. Purkinje fibers (choice C) are specialized cardiac fibers responsible for the rapid conduction of impulses to the myocardial cells, and the atria (choice D) are the upper chambers of the heart involved in receiving blood from the veins.

Correct Answer: A

Rationale: The correct answer is A: Ischemic stroke. Ischemic stroke occurs when a blood clot blocks an artery supplying blood to the brain, leading to brain damage. Choice B, Hemorrhagic stroke, is caused by bleeding in the brain, not a blockage. Choice C, Transient ischemic attack, is a temporary blockage of blood flow to the brain with symptoms similar to a stroke but typically lasting only a few minutes. Choice D, Embolism, refers to a blood clot or other particle that travels through the bloodstream and blocks a blood vessel.