Acetylcholine is not a specific neurotransmitter at:

Correct Answer: B

Rationale: Step-by-step rationale: 1. Acetylcholine is the primary neurotransmitter at sympathetic ganglia, parasympathetic ganglia, and parasympathetic postganglionic nerve endings. 2. However, at sympathetic postganglionic nerve endings, norepinephrine is the primary neurotransmitter. 3. Therefore, the correct answer is B because acetylcholine is not the specific neurotransmitter at sympathetic postganglionic nerve endings. Summary: A, C, and D are incorrect because acetylcholine is indeed the specific neurotransmitter at those locations.

Correct Answer: C

Rationale: The correct answer is C: Beta1 receptor. Stimulation of Beta1 receptors in the heart leads to increased heart rate, contractility, and conduction velocity. This is crucial for the direct effects on the heart. Alpha1 receptors (choice A) primarily cause vasoconstriction, not direct effects on the heart. Alpha2 receptors (choice B) inhibit norepinephrine release and have minimal effects on the heart. Beta2 receptors (choice D) are mainly found in the lungs and blood vessels, leading to bronchodilation and vasodilation, rather than direct effects on the heart.

Correct Answer: A

Rationale: The correct answer is A: Drug-induced parkinsonism. Sympathomimetics stimulate the sympathetic nervous system, which can lead to adverse effects like cerebral hemorrhage, pulmonary edema, myocardial infarction, and ventricular arrhythmias due to increased heart rate and blood pressure. However, they do not cause drug-induced parkinsonism, which is associated with medications that affect dopamine levels in the brain. Therefore, choice A is the correct answer. Choices B, C, and D are incorrect because sympathomimetics can indeed lead to these adverse effects due to their actions on the sympathetic nervous system.

Correct Answer: C

Rationale: The correct answer is C because hypnotic drugs are primarily used to induce drowsiness and promote sleep. They help with insomnia and encourage the onset and maintenance of sleep. This is achieved by affecting the brain's neurotransmitters and promoting relaxation. Options A and D are incorrect as hypnotic drugs are not intended to specifically reduce anxiety, exert a calming effect, or prevent mood swings in patients with bipolar affective disorders. Option B is incorrect as hypnotic drugs do not induce an absence of sensation; that would be more characteristic of anesthetics.

Correct Answer: A

Rationale: Sure! Valproate is the correct answer as it is used as an anti-absence drug due to its effectiveness in treating absence seizures. Valproate works by enhancing the activity of a neurotransmitter called gamma-aminobutyric acid (GABA), which helps to calm overactive brain activity that causes absence seizures. Phenobarbital, Carbamazepine, and Phenytoin are not typically used to treat absence seizures, as they are more commonly used to treat other types of seizures such as tonic-clonic seizures or focal seizures.