The symptoms of mushroom poisoning include all of the following EXCEPT:

Correct Answer: B

Rationale: The correct answer is B because dryness of mouth, hyperpyrexia (high fever), and hallucination are not typical symptoms of mushroom poisoning. Salivation, lacrimation, nausea, vomiting (choice A), headache, abdominal colic (choice C), bradycardia, hypotension, and shock (choice D) are common symptoms seen in mushroom poisoning cases. Dry mouth, high fever, and hallucinations are more likely to be associated with other conditions or toxicities.

Correct Answer: C

Rationale: The correct answer is C: Pupillary dilator muscle. Beta adrenoreceptor subtypes are found in bronchial muscles, heart, and fat cells, but not in pupillary dilator muscles. These receptors are involved in various functions such as bronchodilation, cardiac stimulation, and lipolysis. Pupillary dilator muscles are predominantly innervated by alpha adrenergic receptors, not beta adrenergic receptors, which regulate pupil constriction. Thus, the absence of beta adrenoreceptor subtypes in pupillary dilator muscles makes choice C the correct answer.

Correct Answer: A

Rationale: The correct answer is A: Yohimbine. Yohimbine is an alpha2-selective antagonist because it specifically blocks alpha2-adrenergic receptors. This leads to increased sympathetic activity since alpha2 receptors normally inhibit sympathetic activity when activated. B: Tamsulosin is an alpha1-selective antagonist used to treat benign prostatic hyperplasia. C: Tolazoline is a non-selective alpha-adrenergic antagonist, affecting both alpha1 and alpha2 receptors. D: Prazosin is an alpha1-selective antagonist used to treat hypertension and benign prostatic hyperplasia. In summary, yohimbine is the correct answer because it selectively blocks alpha2 receptors, while the other choices are either alpha1-selective or non-selective alpha antagonists.

Correct Answer: C

Rationale: The correct answer is C: Thyopental. Thyopental is a barbituric acid derivative known for its hypnotic properties by inducing sleep. Flurazepam (A) is a benzodiazepine used for treating insomnia. Zaleplon (B) is a non-benzodiazepine hypnotic agent. Triazolam (D) is also a benzodiazepine used for insomnia. Therefore, the correct choice is C as it is the only barbituric acid derivative among the options.

Correct Answer: A

Rationale: The correct answer is A because phenytoin blocks sodium channels, inhibiting the abnormal firing of neurons seen in epilepsy. This action helps to stabilize neuronal membranes and prevent seizures. Options B, C, and D are incorrect as phenytoin does not bind to GABA receptors, affect Ca2+ currents, or inhibit GABA-transaminase. These mechanisms are associated with different antiepileptic drugs.