Nokea
Which artery generally gives rise to inferior thyroid artery?
- A. External carotid artery
- B. Internal carotid artery
- C. Brachiocephalic trunk
- D. Thyrocervical trunk
Correct Answer: D
Rationale: Step-by-step rationale:
1. The inferior thyroid artery typically arises from the thyrocervical trunk.
2. The thyrocervical trunk is a branch of the subclavian artery.
3. This artery supplies blood to the thyroid gland.
4. The external carotid artery and internal carotid artery do not give rise to the inferior thyroid artery.
5. The brachiocephalic trunk does not directly supply blood to the thyroid gland.
In conclusion, the correct answer is D because the thyrocervical trunk is the main artery that gives rise to the inferior thyroid artery, providing blood supply to the thyroid gland.
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A drug useful in the treatment of acute attack of migraine is:
- A. Sumatriptan
- B. Ergometrine
- C. Dihydroergometrine
- D. Propranolol
Correct Answer: A
Rationale: Sumatriptan is the correct answer for treating acute migraine attacks as it is a specific serotonin receptor agonist that helps constrict blood vessels in the brain. Ergometrine and dihydroergometrine are ergot alkaloids used for other conditions, not migraine. Propranolol is a beta-blocker used for migraine prevention, not acute attacks.
Calcium level in the blood is regulated by the:
- A. Parathyroid and thyroid
- B. Adrenal medulla and pancreas
- C. Testes
- D. Parathyroid and thymus
Correct Answer: A
Rationale: The correct answer is A: Parathyroid and thyroid. The parathyroid glands secrete parathyroid hormone, which increases blood calcium levels by promoting calcium release from bones and increasing calcium absorption in the intestines. The thyroid gland produces calcitonin, which lowers blood calcium levels by inhibiting bone breakdown and increasing calcium excretion by the kidneys. The adrenal medulla and pancreas do not play a direct role in regulating calcium levels. Testes are not involved in calcium regulation. The thymus is responsible for developing T-cells and does not have a role in calcium regulation.
Which one of the following is a cardio selective β1-blocker:
- A. Timolol
- B. Metoprolol
- C. Nadolol
- D. Sotalol
Correct Answer: B
Rationale: The correct answer is B: Metoprolol. Metoprolol is a cardioselective beta-1 blocker, meaning it primarily blocks beta-1 receptors in the heart, leading to a decrease in heart rate and contractility. This selectivity reduces the risk of bronchoconstriction compared to non-selective beta blockers like Timolol (Choice A), Nadolol (Choice C), and Sotalol (Choice D), which can also block beta-2 receptors in the lungs, potentially causing respiratory issues in patients with asthma or COPD. Therefore, Metoprolol is the best choice for patients with cardiovascular conditions who also have respiratory concerns.
What is the mass of hydrogen chloride that reacts with 5.1 g of ammonia?
- A. 3.65g
- B. 10.95g
- C. 7.05g
- D. 21.15g
Correct Answer: B
Rationale: To find the mass of hydrogen chloride that reacts with 5.1g of ammonia, we need to use the stoichiometry of the balanced chemical equation. The balanced equation for the reaction between ammonia (NH3) and hydrogen chloride (HCl) is:
NH3 + HCl → NH4Cl
From the equation, we can see that 1 mole of NH3 reacts with 1 mole of HCl to form 1 mole of NH4Cl. Therefore, the molar ratio of NH3 to HCl is 1:1.
First, we need to convert the given mass of ammonia (5.1g) to moles using the molar mass of ammonia (17g/mol):
5.1g NH3 * (1 mol NH3 / 17g NH3) = 0.3 mol NH3
Since the molar ratio of NH3 to HCl is 1:1, the moles of HCl that react with
Underproduction of growth hormone during the growing years produces ______.
- A. myxedema.
- B. gigantism.
- C. pituitary dwarfism.
- D. acromegaly.
Correct Answer: C
Rationale: The correct answer is C: pituitary dwarfism. Growth hormone deficiency during growing years results in pituitary dwarfism due to stunted growth. Myxedema (choice A) is associated with hypothyroidism, not growth hormone deficiency. Gigantism (choice B) occurs due to excessive growth hormone production in childhood. Acromegaly (choice D) is caused by excess growth hormone in adulthood, not during the growing years. Thus, choice C is the most appropriate based on the impact of growth hormone deficiency on growth during childhood.