Which of the following antianginal agents is a beta-adrenoceptor-blocking drug:

Correct Answer: C

Rationale: Rationale: Atenolol is a beta-adrenoceptor-blocking drug, specifically a beta-1 selective blocker. It works by reducing the heart rate and blood pressure, making it effective in treating angina. Dipyridamole is a vasodilator, not a beta blocker. Validol is a mild sedative and antispasmodic, not a beta blocker. Alinidine is an antiarrhythmic drug acting on the alpha-2 adrenergic receptors, not a beta blocker. Therefore, Atenolol is the correct choice as it directly targets beta-adrenoceptors to reduce anginal symptoms.

Correct Answer: A

Rationale: The correct answer is A. Daily administration of large doses of iodides causes involution of the thyroid gland. Iodides inhibit thyroid hormone synthesis, leading to a decrease in thyroid size. This effect peaks in about two weeks. Choice B is incorrect as iodides actually decrease vascularity of the thyroid gland. Choice C is incorrect because iodides increase the storage of colloid in the thyroid gland. Choice D is incorrect as iodides make the thyroid gland softer and more vascular, not firm and less vascular.

Correct Answer: A

Rationale: Rationale: Answer A is correct as it accurately defines inflammation as a localized protective response to irritation, injury, or infection. Pain, redness, swelling, and loss of function are typical characteristics. Answer B is incorrect as inflammation is not a deficiency of the immune response. Answer C is incorrect as it describes an autoimmune reaction, not inflammation. Therefore, the correct answer is A.

Correct Answer: A

Rationale: The correct answer is A because H1 histamine receptors are primarily found in smooth muscle, endothelium, and the brain. Smooth muscle and endothelium are major sites of action for H1 receptors, regulating functions like vasodilation and bronchoconstriction. The presence of H1 receptors in the brain also plays a role in neurotransmission. Choice B is incorrect because gastric mucosa, cardiac muscle, and mast cells are associated with H2 histamine receptors, not H1. Choice C is incorrect because presynaptic H3 receptors are found in the brain, whereas H1 receptors are primarily postsynaptic. Choice D is incorrect because not all locations listed in the other choices are where H1 receptors are predominantly found.

Correct Answer: A

Rationale: Step 1: Define hypervitaminosis as excessive intake of a vitamin leading to pathological effects. Step 2: Given definition matches the statement, making it True. Step 3: Other choices do not align with the definition; 'False' is opposite, 'All' and 'None' are generalizations not specific to the context. In summary, choice A is correct as it accurately reflects the definition of hypervitaminosis, while the other choices are incorrect due to being unrelated or too general.