Nokea
Which one of the following properties makes labetalol different from nearly all the other β-blockers on the market?
- A. Also blocks alpha-adrenergic receptors
- B. Causes strong atropine-like side effects, has same side effects as atropine
- C. Only blocks β1 receptors
- D. Safe for asthmatics because it lacks β2 blocking activity
Correct Answer: A
Rationale: The correct answer is A because labetalol is unique among most β-blockers as it also blocks alpha-adrenergic receptors. This dual action results in vasodilation and reduced blood pressure. Choice B is incorrect as labetalol does not cause atropine-like side effects. Choice C is incorrect as labetalol blocks both β1 and β2 receptors. Choice D is also incorrect as labetalol does have some β2 blocking activity, making it not entirely safe for asthmatics.
You may also like to solve these questions
Hypothyroidism in adults due to an underactive thyroid is ____.
- A. Graves disease.
- B. diabetes insipidus.
- C. myxedema
- D. acromegaly.
Correct Answer: C
Rationale: The correct answer is C: myxedema. Hypothyroidism in adults is commonly caused by an underactive thyroid gland, leading to decreased production of thyroid hormones. Myxedema is the term used to describe severe hypothyroidism, characterized by symptoms such as fatigue, weight gain, cold intolerance, and swelling of the face and hands. Graves disease (choice A) is actually a cause of hyperthyroidism, not hypothyroidism. Diabetes insipidus (choice B) is a disorder related to the kidneys and has no direct connection to thyroid function. Acromegaly (choice D) is caused by excess growth hormone production, unrelated to thyroid function. Therefore, the correct choice is C as it accurately describes hypothyroidism in adults.
Which of the following is descriptive of prolactin?
- A. Secreted by the posterior pituitary gland.
- B. Also called lactogenic hormone.
- C. Causes the milk let-down reflex.
- D. Stimulates the neurohypophysis to synthesize oxytocin.
Correct Answer: B
Rationale: Step-by-step rationale:
1. Prolactin is also called lactogenic hormone, as it promotes milk production in the mammary glands.
2. Secreted by the anterior pituitary gland, not the posterior pituitary gland.
3. Milk let-down reflex is primarily controlled by oxytocin, not prolactin.
4. Prolactin does not stimulate the neurohypophysis (posterior pituitary) to synthesize oxytocin.
Summary:
Choice B is correct because it accurately describes the function of prolactin in promoting lactation. Choices A, C, and D are incorrect due to inaccuracies in the functions and secretion of prolactin.
Which organ does not have hormone production?
- A. heart
- B. kidney
- C. liver
- D. skin
Correct Answer: C
Rationale: The correct answer is C: liver. The liver does not produce hormones. Hormones are primarily produced by endocrine glands such as the pituitary, thyroid, adrenal glands, etc. The liver's main functions are related to metabolism, detoxification, and storage, rather than hormone production. The heart (choice A) produces hormones like atrial natriuretic peptide. The kidney (choice B) produces hormones like erythropoietin and renin. The skin (choice D) produces hormones like vitamin D when exposed to sunlight. Therefore, the liver is the only organ in the list that does not have hormone production.
Hormones produced by the hypothalamus and secreted by the posterior pituitary include:
- A. ADH and aldosterone
- B. ADH and oxytocin
- C. oxytocin and prolactin
- D. cortisol and aldosterone
Correct Answer: B
Rationale: Step 1: The hormones produced by the hypothalamus and secreted by the posterior pituitary are ADH (vasopressin) and oxytocin.
Step 2: ADH regulates water balance by increasing water reabsorption in the kidneys.
Step 3: Oxytocin is involved in uterine contractions during childbirth and milk ejection during breastfeeding.
Step 4: Therefore, choice B (ADH and oxytocin) is correct.
Summary:
- Choice A (ADH and aldosterone) is incorrect because aldosterone is produced by the adrenal glands, not the posterior pituitary.
- Choice C (oxytocin and prolactin) is incorrect because prolactin is produced by the anterior pituitary.
- Choice D (cortisol and aldosterone) is incorrect because cortisol is produced by the adrenal glands, not the posterior pituitary.
Atropine is used in the treatment of:
- A. Tachycardia
- B. Glaucoma
- C. Intestinal colic
- D. Enlarged prostate
Correct Answer: C
Rationale: Atropine is used in the treatment of intestinal colic due to its ability to relax smooth muscles, including those in the gastrointestinal tract. It helps relieve spasms and pain associated with intestinal colic. Tachycardia is usually treated with beta-blockers, not atropine. Glaucoma is treated with medications that reduce intraocular pressure, not atropine. Enlarged prostate is typically managed with medications that target prostate enlargement, not atropine. Therefore, the correct choice is C: Intestinal colic.