Correct Answer: A

Rationale: The correct answer is A: Transient ischemic attack (TIA). A transient ischemic attack (TIA) is often called a 'mini-stroke' because it is characterized by a temporary interruption of blood flow to the brain, resulting in stroke-like symptoms that typically resolve within a short period. Choice B, 'Stroke,' is incorrect because a stroke involves a more prolonged interruption of blood flow, leading to lasting brain damage. Choices C and D, 'Myocardial infarction' and 'Pulmonary embolism,' are unrelated conditions involving the heart and lungs, respectively, and do not describe a temporary interruption of blood flow to the brain.

Correct Answer: A

Rationale: Bronchodilators are medications that relax the muscles around the airways, improving airflow and making breathing easier for patients with asthma or COPD. Corticosteroids are anti-inflammatory drugs used to reduce airway inflammation, while mucolytics help in thinning and clearing mucus. Antihistamines are used to treat allergies and not specifically to improve breathing in conditions like asthma or COPD.

Correct Answer: D

Rationale: The correct answer is D: Decreases blood pressure. Calcium channel blockers primarily work by relaxing the blood vessels, leading to a decrease in blood pressure. Choice A, 'Decreases heart rate,' is incorrect because calcium channel blockers do not significantly affect heart rate. Choice B, 'Increases heart rate,' is incorrect as calcium channel blockers do not have a primary effect of increasing heart rate. Choice C, 'Increases blood pressure,' is incorrect as the primary effect of calcium channel blockers is to decrease blood pressure by vasodilation.

Correct Answer: A

Rationale: The correct answer is A: Cough. Enalapril is an ACE inhibitor, and cough is a common side effect associated with this class of medication. Monitoring for cough is crucial as it can indicate the development of a potentially serious condition known as angioedema. Hyperkalemia (choice B) is a possible side effect of ACE inhibitors but is not the most important side effect to monitor. Hypotension (choice C) and dizziness (choice D) are also potential side effects of enalapril; however, cough takes precedence due to its association with angioedema, a severe adverse reaction.

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.