Correct Answer: A

Rationale: The correct answer is A, Coronary artery disease (CAD). CAD specifically refers to the condition where the arteries supplying blood to the heart become narrowed or blocked by plaque buildup. Choice B, Atherosclerosis, is a general term for the hardening and narrowing of arteries due to plaque buildup but does not specifically mention the heart. Choice C, Peripheral artery disease, involves narrowing of arteries that supply blood to areas other than the heart. Choice D, Congestive heart failure, is a condition where the heart is unable to pump blood effectively but is not primarily caused by narrowed or blocked arteries.

Correct Answer: A

Rationale: The correct answer is A: Heart failure. Heart failure occurs when the heart is unable to pump blood effectively, resulting in a buildup of fluid in the lungs and other parts of the body. Choice B, Cardiomyopathy, refers to diseases of the heart muscle, not specifically the inability to pump blood effectively. Choice C, Myocardial infarction, is a heart attack caused by a blocked blood supply to the heart muscle, not directly related to the heart's pumping efficiency. Choice D, Pulmonary edema, is a condition characterized by fluid accumulation in the lungs, often a consequence of heart failure but not the primary condition described in the question.

Correct Answer: A

Rationale: The correct answer is A, Tuberculosis. Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis, primarily affecting the lungs but can spread to other organs. Choice B, Pneumonia, is an infection that inflames the air sacs in one or both lungs. Choice C, Legionnaires' disease, is a severe form of pneumonia caused by the Legionella bacteria. Choice D, Histoplasmosis, is a fungal infection caused by inhaling spores of the Histoplasma capsulatum fungus.

Correct Answer: A

Rationale: The correct answer is the Sympathetic nervous system. The sympathetic nervous system is a branch of the autonomic nervous system that is responsible for the fight-or-flight response. It causes vasodilation in central vessels to increase blood flow to vital organs during stress or exercise, while inducing vasoconstriction in peripheral vessels to redirect blood to essential areas. Norepinephrine and acetylcholine are neurotransmitters associated with the sympathetic and parasympathetic nervous systems, respectively, but they are not themselves central vasodilators and peripheral vasoconstrictors.

Correct Answer: A

Rationale: The correct answer is A: Platelet count. When administering enoxaparin, it is crucial to monitor the platelet count because enoxaparin can lead to a rare but serious side effect known as thrombocytopenia, which is a decrease in platelet levels. Monitoring the platelet count helps in detecting this adverse effect early. Choices B, C, and D are incorrect because hemoglobin, white blood cell count, and aPTT are not the most important lab values to monitor specifically for enoxaparin administration.