Indicate the location of M2 cholinoreceptor type:

Correct Answer: A

Rationale: The correct answer is A: Heart. M2 cholinoreceptors are primarily located in the heart. These receptors are involved in regulating heart rate and contractility by inhibiting adenylate cyclase activity. This leads to decreased cAMP levels, resulting in a decrease in heart rate and contractility. The other choices (B: Glands, C: Smooth muscle, D: Endothelium) are incorrect as M2 receptors are not typically found in these locations. In glands, M3 receptors are more common, in smooth muscle M3 receptors predominate, and in the endothelium, muscarinic receptors are not the primary receptors involved in regulation.

Correct Answer: A

Rationale: The correct answer is A: Heart. Alpha adrenoreceptor subtypes are mainly associated with smooth muscle tissues, not cardiac muscle like the heart. Alpha-1 receptors are present in blood vessels, prostate, and pupillary dilator muscle, helping in vasoconstriction, ejaculation, and pupil dilation respectively. Alpha-2 receptors are also found in these tissues, modulating neurotransmitter release and smooth muscle contraction. The heart primarily contains beta adrenoreceptor subtypes, which regulate heart rate and contractility. Therefore, the distribution of alpha adrenoreceptor subtypes is not associated with the heart.

Correct Answer: C

Rationale: Rationale: 1. Prazosin is an alpha1-selective antagonist used to treat hypertension by blocking alpha1 receptors in blood vessels. 2. Phentolamine (A) is a non-selective alpha-blocker. 3. Dihydroergotamine (B) is a 5-HT1 receptor agonist used for migraine. 4. Labetalol (D) is a non-selective alpha and beta blocker. Therefore, C (Prazosin) is the correct answer as it is a selective alpha1 blocker.

Correct Answer: B

Rationale: The correct answer is B: Flurazepam. Flurazepam is a benzodiazepine derivative because it contains a benzodiazepine ring structure in its chemical composition. Benzodiazepines are a class of drugs commonly used as hypnotics due to their sedative and hypnotic effects. Zolpidem (A) is a non-benzodiazepine hypnotic drug, while Secobarbital (C) and Phenobarbitone (D) are barbiturates, not benzodiazepines. Benzodiazepines are preferred over barbiturates for hypnotic use due to their lower risk of respiratory depression and overdose.

Correct Answer: C

Rationale: The correct answer is C: Diazepam. Diazepam is the most effective drug for stopping generalized tonic-clonic status epilepticus in adults due to its rapid onset of action and ability to terminate seizures quickly. It works by enhancing the inhibitory neurotransmitter GABA in the brain, suppressing seizure activity. Lamotrigine (A) is not recommended for acute seizure control. Ethosuximide (B) is used for absence seizures, not generalized tonic-clonic seizures. Zonisamide (D) has a slower onset of action and is not the first-line treatment for status epilepticus.