A teratogenic action is:

Correct Answer: B

Rationale: The correct answer is B because a teratogenic action refers to substances or factors that can negatively affect the fetus during pregnancy, leading to fetal malformations or abnormalities. This is a well-established concept in the field of developmental biology and teratology. Options A, C, and D are incorrect as they do not specifically pertain to the impact on fetal development, which is the defining characteristic of teratogenic actions. Option A focuses on the liver, Option C on the blood system, and Option D on the kidneys, none of which directly relate to the concept of teratogenicity.

Correct Answer: D

Rationale: Atropine is rarely used for peptic ulcer treatment due to its adverse effects, which include slow gastric emptying leading to prolonged exposure of the ulcer bed to acid, low efficiency requiring large doses, and other possible side effects. Therefore, the correct answer is D as it encompasses all the reasons why atropine is not commonly used for peptic ulcer treatment. Choices A, B, and C individually address specific drawbacks of atropine, but only D covers all the reasons comprehensively.

Correct Answer: B

Rationale: The correct answer is B: α2 receptor. Epinephrine binds to α2 receptors, leading to inhibition of adenylate cyclase activity, which decreases intracellular cAMP levels. α1 receptors are Gq-coupled and increase intracellular calcium levels. Beta1 receptors are also Gs-coupled, leading to increased cAMP levels. Beta2 receptors, like α2 receptors, are Gi-coupled and decrease cAMP levels. Therefore, the correct answer is B because epinephrine acts on α2 receptors to decrease cAMP levels.

Correct Answer: B

Rationale: The correct answer is B: Phenylephrine. Phenylephrine is an effective mydriatic because it acts on alpha-1 adrenergic receptors in the eye, causing pupillary dilation. Salmeterol (A) is a long-acting beta-2 agonist used for asthma, not mydriasis. Dobutamine (C) is a beta-1 agonist used for cardiac support. Norepinephrine (D) is a non-selective adrenergic agonist used for hypotension, not for mydriasis.

Correct Answer: B

Rationale: The correct answer is B: Sleep disorders. Hypnotic drugs are primarily used to treat sleep disorders by promoting sleep or helping to manage insomnia. They act on the central nervous system to induce and maintain sleep. Psychosis (A) is typically treated with antipsychotic medications, narcolepsy (C) is treated with stimulant medications, and Parkinsonian disorders (D) are managed with medications that target dopamine levels in the brain. Therefore, the correct choice is B as it aligns with the pharmacological action and intended therapeutic effect of hypnotic drugs.