Main clinical use of calcium channel blockers is:

Correct Answer: D

Rationale: The correct answer is D, "All of the above." Calcium channel blockers are commonly used for angina pectoris, hypertension, and supraventricular tachyarrhythmias. They work by blocking the entry of calcium into the cells, leading to vasodilation, decreased myocardial contractility, and reduced heart rate. This helps in managing angina by reducing oxygen demand, controlling blood pressure, and treating certain types of arrhythmias. Therefore, the main clinical use of calcium channel blockers encompasses all three conditions mentioned in the choices.

Correct Answer: A

Rationale: The correct answer is A: Iodide 1 part in 100000. In an area where goitre is endemic, iodide is used to treat iodine deficiency, which is a common cause of goitre. Iodide supplementation helps in restoring normal thyroid function by providing the necessary iodine for thyroid hormone synthesis. Propylthiouracil and Methimazole are used to treat hyperthyroidism, not goitre. Therefore, they are incorrect choices. Option D is incorrect because not all the choices can be used interchangeably for treating goitre.

Correct Answer: D

Rationale: The correct answer is D because the statement is false. The triphasic pill does not contain luteinizing hormone (LH). The triphasic pill contains varying levels of estrogen and progestin throughout the cycle to mimic the natural hormonal fluctuations in a woman's menstrual cycle. A: The combination pill does contain both estrogen and progestin, making statement A true. B: Ethinyl estradiol and mestranol are indeed commonly used in oral contraceptives, making statement B true. C: The minipill contains progestin alone, making statement C true. In summary, the incorrect statement is D because the triphasic pill does not contain luteinizing hormone. Statements A, B, and C are all true regarding oral contraceptives.

Correct Answer: B

Rationale: The correct answer is B because immunodeficiency refers to a disorder or deficiency in the normal immune response. This means that the immune system is not functioning properly, leading to increased susceptibility to infections and other health issues. Choice A describes inflammation, not immunodeficiency. Choice C describes autoimmune disease, which is different from immunodeficiency. Choice D is incorrect because not all the statements are related to immunodeficiency. In summary, the correct answer is B because it directly relates to a malfunction in the immune system, while the other choices describe different processes or conditions.

Correct Answer: A

Rationale: The correct answer is A because antienzymes are agents that inhibit or destroy enzymic activity. They can be inhibitory enzymes or antibodies that target specific enzymes. This definition aligns with the concept of antienzymes acting to retard or inhibit enzymatic activity. Choice B is incorrect because substances that prevent vitamins from exerting their effects are not related to antienzymes. Choice C describes enzymes, not antienzymes, which are the opposite in function. Choice D refers to coenzymes, which are required for enzyme activity, not antienzymes that inhibit or destroy enzymic activity.