Which of the following inhaled anesthetics increases cerebral blood flow least of all?

Correct Answer: A

Rationale: The correct answer is A: Sevoflurane. Sevoflurane is the inhaled anesthetic that increases cerebral blood flow the least due to its minimal effect on cerebral vasodilation. Sevoflurane has a lower blood-gas partition coefficient compared to the other choices, resulting in faster onset and offset of action. This rapid clearance from the blood reduces its impact on cerebral blood flow. In contrast, Nitrous oxide (Choice B) is a potent cerebral vasodilator, Isoflurane (Choice C) and Desflurane (Choice D) also have higher blood-gas partition coefficients leading to more significant effects on cerebral blood flow compared to Sevoflurane.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Ticlopidine is a thienopyridine derivative that inhibits ADP-induced platelet aggregation. 2. By inhibiting the binding of ADP to its platelet receptor, it prevents platelet activation and aggregation. 3. This mechanism of action makes ticlopidine an effective antiplatelet medication for preventing clot formation. 4. Therefore, the statement that ticlopidine is an inhibitor of ADP-induced platelet aggregation is TRUE. Summary of other choices: - Choice B (FALSE): This is incorrect as ticlopidine is indeed an inhibitor of ADP-induced platelet aggregation. - Choice C (All): This is incorrect as ticlopidine is not classified as affecting all types of platelet aggregation. - Choice D (None of the above): This is incorrect as the correct answer is A, making this choice invalid.

Correct Answer: B

Rationale: The correct answer is B: Verapamil. Verapamil is a calcium channel blocker that slows conduction through the AV node, making it effective in terminating supraventricular tachycardias. Nifedipine, choice A, is also a calcium channel blocker but is not typically used intravenously for this purpose. Choice C is incorrect because only Verapamil is specifically indicated for terminating supraventricular tachycardias. Choice D is incorrect as Verapamil is the correct drug for this scenario.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Nifedipine is a calcium channel blocker that causes vasodilation. 2. Vasodilation leads to a decrease in blood pressure. 3. To compensate, the body may exhibit reflex tachycardia. 4. Therefore, nifedipine routinely produces tachycardia. Summary of incorrect choices: A. Propranolol is a beta-blocker that slows heart rate. B. Clonidine is a centrally-acting alpha-2 agonist that decreases sympathetic outflow, leading to bradycardia. C. Enalapril is an ACE inhibitor that does not directly affect heart rate.

Correct Answer: D

Rationale: The correct answer is D, the mammary gland. Prolactin is a hormone primarily responsible for mammary gland development and milk production in females. It stimulates the mammary alveolar cells to produce milk. The other choices, A: Liver, B: Adrenal cortex, and C: Thyroid, are not directly targeted by prolactin and do not have a primary role in milk production. Therefore, the correct answer is D as it directly correlates with the function of prolactin in the body.