The symptoms of excessive stimulation of muscarinic receptors include all of the following EXCEPT:

Correct Answer: D

Rationale: The correct answer is D: Weakness of all skeletal muscles. Excessive stimulation of muscarinic receptors would not lead to weakness of skeletal muscles because muscarinic receptors are mainly found in smooth muscles and glands, not skeletal muscles. A: Abdominal cramps, diarrhea, B: Increased salivation, excessive bronchial secretion, and C: Miosis, bradycardia are all symptoms of excessive muscarinic receptor stimulation as these receptors are involved in various functions in the body such as gastrointestinal motility, salivation, bronchial secretions, pupil constriction, and heart rate regulation.

Correct Answer: C

Rationale: Rationale: 1. Phenylephrine is a relatively pure alpha agonist, constricts blood vessels, and increases blood pressure. 2. It is an effective mydriatic due to its alpha-adrenergic effects. 3. Phenylephrine is a decongestant by constricting nasal blood vessels. 4. Epinephrine and norepinephrine are non-selective agonists with more diverse effects. 5. Ephedrine acts on both alpha and beta receptors, making it less specific for raising blood pressure.

Correct Answer: C

Rationale: The correct answer is C because beta-blocking agents do not induce depression or deplete stores of catecholamines. Here's the rationale: 1. Option A is correct as beta blockers occupy beta receptors, competitively reducing receptor occupancy by catecholamines. 2. Option B is incorrect because beta blockers can cause hypotension as one of their side effects, especially in individuals with normal blood pressure. 3. Option D is correct as beta blockers can cause blockade in the atrioventricular node, leading to decreased heart rate and conduction. In summary, beta blockers do not induce depression or deplete catecholamine stores, making option C the correct answer.

Correct Answer: D

Rationale: The correct answer is D because an ideal hypnotic agent should have all the qualities listed in choices A, B, and C. Rapid onset and sufficient duration of action ensure quick and long-lasting sleep induction. Minor effects on sleep patterns indicate minimal disruption to natural sleep cycles. Minimal "hangover" effects mean fewer side effects upon waking up, promoting overall well-being. Therefore, having all these qualities makes a hypnotic agent ideal for promoting healthy and restful sleep.

Correct Answer: D

Rationale: The correct answer is D: Lorazepam. Lorazepam is a benzodiazepine receptor agonist, which enhances the inhibitory effect of GABA in the brain, reducing neuronal excitability and preventing seizures. Phenobarbital (A) acts by enhancing GABAergic transmission but is not a benzodiazepine. Phenytoin (B) works by blocking sodium channels. Carbamazepine (C) also blocks sodium channels but is not a benzodiazepine receptor agonist. Therefore, D is the correct answer as it directly acts on the benzodiazepine receptor to control seizures.