The effect of the drug on parasympathetic function declines rapidly in all organs EXCEPT:

Correct Answer: A

Rationale: The correct answer is A: Eye. The parasympathetic nervous system controls functions like pupil constriction in the eye. This effect is mediated by the neurotransmitter acetylcholine. The eye has a unique structure called the iris sphincter muscle, which responds to parasympathetic stimulation by constricting the pupil. Unlike other organs, the effect on the eye is not subject to rapid decline, as the iris sphincter muscle has a high sensitivity to acetylcholine. Therefore, the parasympathetic function in the eye does not decline rapidly compared to other organs. Summary of other choices: B: Heart - Parasympathetic control of heart rate can decline rapidly due to factors like decreased acetylcholine release. C: Smooth muscle organs - Parasympathetic control of smooth muscle organs can also decline rapidly due to factors like receptor desensitization. D: Glands - Parasympathetic control of glands can

Correct Answer: B

Rationale: The correct answer is B: Dobutamine. In cardiogenic shock, dobutamine is preferred due to its positive inotropic effects, which increase contractility and cardiac output. Epinephrine (A) has potent vasoconstrictive effects that may worsen coronary perfusion. Isoproterenol (C) can lead to tachycardia and worsen myocardial oxygen demand. Methoxamine (D) is a vasoconstrictor and may further decrease cardiac output in cardiogenic shock. In summary, dobutamine is preferred for cardiogenic shock due to its positive inotropic effects without significant vasoconstriction or tachycardia.

Correct Answer: B

Rationale: The correct answer is B because pindolol and oxprenolol are both partial agonists at beta-adrenergic receptors. This means they have intrinsic sympathomimetic activity. This property sets them apart from other beta blockers that do not have partial agonist activity. A: They are nonselective beta antagonists - True, they block both beta-1 and beta-2 receptors. C: They are less likely to cause bradycardia and abnormalities in plasma lipids - True, due to their partial agonist activity. D: They are effective in hypertension and angina - True, they are used for these conditions.

Correct Answer: A

Rationale: The correct answer is A: Thiopental. Thiopental is used intravenously as anesthesia due to its rapid onset and short duration of action, making it suitable for induction of anesthesia. Phenobarbital, Flurazepam, and Zolpidem are not typically used for anesthesia due to slower onset, longer duration, and different mechanisms of action. Thiopental's pharmacokinetic profile and effectiveness in inducing anesthesia make it the most appropriate choice among the options provided.

Correct Answer: B

Rationale: The correct answer is B: Carbamazepine. Carbamazepine is the first-line treatment for trigeminal neuralgia due to its efficacy in reducing nerve firing and alleviating neuropathic pain. It works by blocking sodium channels in neurons. Lamotrigine (A) is more commonly used for epilepsy. Topiramate (C) is effective for migraine prevention but less so for trigeminal neuralgia. Valproate (D) is not typically used for trigeminal neuralgia.