Which synapses are involved in depression?

Correct Answer: D

Rationale: The correct answer is D because depression is a complex condition involving various neurotransmitters. Dopamine, serotonin, and acetylcholine play key roles in regulating mood and emotions. Dysfunction in any of these synapses can contribute to depressive symptoms. Therefore, all the options (A, B, and C) are involved in depression. Dopaminergic synapses are linked to motivation and pleasure, serotoninergic synapses are associated with mood regulation, and cholinergic synapses are involved in cognitive function and memory. Therefore, it is crucial to consider the interplay of all these neurotransmitters in understanding and treating depression.

Correct Answer: D

Rationale: The correct answer is D because barbiturate abstinent syndrome can manifest as a variety of symptoms including crisis by 3 days of abstention, anxiety, mydriasis, myasthenia, muscular convulsions, vomiting, diarrhea, and psychosis as delirium with color visual and auditory hallucinations. Each of the other choices (A, B, C) only represents a subset of the symptoms associated with barbiturate abstinent syndrome, while choice D encompasses all possible manifestations, making it the correct and comprehensive answer.

Correct Answer: A

Rationale: The correct answer is A: Libexine. Non-narcotic antitussives, such as Libexine, do not contain opioids or narcotics, making them safer for use without the risk of dependence or addiction. Libexine works by suppressing the cough reflex in the brainstem without causing sedation or respiratory depression. Choice B, Tusuprex, is incorrect as it contains codeine, which is a narcotic antitussive. Choice C, Codeine, is also incorrect as it is a narcotic antitussive that acts on the central nervous system to suppress cough reflex. Choice D, Aethylmorphine hydrochloride, is incorrect as it is a semi-synthetic opioid derivative, making it a narcotic antitussive.

Correct Answer: A

Rationale: The correct answer is A: Phenolphthalein. Phenolphthalein is a stimulant laxative that irritates the gut lining, leading to increased peristalsis and bowel movements. This mechanism helps relieve constipation. Methyl cellulose (B) is a bulk-forming laxative that works by absorbing water to form a soft bulk, not by irritating the gut. Proserine (C) is a cholinesterase inhibitor used for myasthenia gravis, not for gut stimulation. Mineral oil (D) is a lubricant laxative that works by coating the stool and preventing water absorption, not by irritating the gut.

Correct Answer: B

Rationale: The correct answer is B: Digitoxin is greater than digoxin. This is because digitoxin has a longer half-life compared to digoxin. Digitoxin is a more potent cardiac glycoside with a slower elimination rate, leading to a longer duration of action in the body. Digoxin, on the other hand, has a shorter half-life and is eliminated more rapidly. Therefore, digitoxin remains in the body for a longer duration, making it have a greater half-life compared to digoxin. Choices A, C, and D are incorrect as they do not relate to the comparison of half-lives between digoxin and digitoxin.