Nokea
A 38-year-old man with galactorrhea is treated with bromocriptine, which eliminates the galactorrhea. The basis for the therapeutic action of bromocriptine is that it
- A. antagonizes the action of prolactin on the breast
- B. enhances the action of prolactin on the breast
- C. inhibits prolactin release from the anterior pituitary
- D. inhibits prolactin release from the hypothalamus
Correct Answer: C
Rationale: Step-by-step rationale:
1. Bromocriptine is a dopamine agonist.
2. Dopamine inhibits prolactin release from the anterior pituitary.
3. Galactorrhea is often caused by excess prolactin.
4. By inhibiting prolactin release, bromocriptine reduces prolactin levels and eliminates galactorrhea.
Summary:
A: Incorrect - Bromocriptine does not antagonize prolactin action.
B: Incorrect - Bromocriptine does not enhance prolactin action.
D: Incorrect - Prolactin is not released from the hypothalamus.
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With regard to carbohydrate digestion:
- A. salivary amylase works best at alkaline pH
- B. approximately 40% of adult Europeans are lactose intolerant
- C. oligosaccharidase deficiency results in osmotic diarrhoea
- D. salivary amylase continues to digest carbohydrates in the stomach
Correct Answer: C
Rationale: Rationale for Correct Answer C: Oligosaccharidase deficiency leads to osmotic diarrhea because the incomplete breakdown of oligosaccharides in the small intestine results in unabsorbed sugars attracting water, causing diarrhea. This is a direct consequence of the deficiency in enzymes responsible for breaking down oligosaccharides. This is why Choice C is correct.
Summary of Incorrect Choices:
A: Salivary amylase works best at a neutral pH of around 6.7, not alkaline pH.
B: Lactose intolerance is due to a deficiency in lactase enzyme, not related to carbohydrate digestion in the small intestine.
D: Salivary amylase is inactivated in the acidic environment of the stomach, so it does not continue to digest carbohydrates there.
Which if the following gland which can be classified as an endocrine and an exocrine gland?
- A. Thyroid.
- B. Thymus.
- C. Pancreas.
- D. Pituitary.
Correct Answer: C
Rationale: The correct answer is C: Pancreas. The pancreas is both an endocrine and exocrine gland. It secretes hormones like insulin and glucagon (endocrine function) into the bloodstream to regulate blood sugar levels, while also producing digestive enzymes (exocrine function) that are released into the small intestine to aid in digestion. The other choices are incorrect because:
A: Thyroid - primarily an endocrine gland that produces hormones like thyroxine.
B: Thymus - strictly an endocrine gland responsible for T-cell development.
D: Pituitary - also an endocrine gland that controls various other endocrine glands in the body.
Which layer of cervical fascia forms the false capsule of thyroid gland?
- A. Carotid sheath
- B. Investing layer
- C. Pretracheal fascia
- D. Prevertebral fascia
Correct Answer: C
Rationale: The correct answer is C: Pretracheal fascia. This layer surrounds the thyroid gland, forming the false capsule. It separates the thyroid from the strap muscles anteriorly and the trachea and esophagus posteriorly. The Carotid sheath (A) encloses the common carotid artery, internal jugular vein, and vagus nerve. The Investing layer (B) covers the sternocleidomastoid and trapezius muscles. The Prevertebral fascia (D) surrounds the vertebral column and deep neck muscles, not directly related to the thyroid gland.
The endocrine system works together with the ________ system to maintain the body’s equilibrium?
- A. digestive system
- B. nervous system
- C. respiratory system
- D. reproductive system
Correct Answer: B
Rationale: The correct answer is B: nervous system. The endocrine system and nervous system work together in maintaining the body's equilibrium through communication and regulation of bodily functions. The nervous system controls rapid responses, while the endocrine system regulates slower, long-term responses through hormones. The digestive system (A) primarily focuses on breaking down food and absorbing nutrients. The respiratory system (C) is responsible for gas exchange. The reproductive system (D) is involved in reproduction and hormone production, but not in maintaining the body's equilibrium.
A 32-year-old woman presents with a blood pressure of 155/96 mm Hg. In response to questioning, she admits that she loves licorice and eats some at least three times a week. She probably has a low level of
- A. type 2 11β-hydroxysteroid dehydrogenase activity
- B. ACTH
- C. 11β-hydroxylase activity
- D. glucocorticoid transferase
Correct Answer: A
Rationale: The correct answer is A: type 2 11β-hydroxysteroid dehydrogenase activity. Licorice contains glycyrrhizin, which inhibits this enzyme, leading to increased levels of cortisol and mineralocorticoids. This explains the elevated blood pressure in the patient. Choice B, ACTH, is incorrect because licorice consumption does not directly affect ACTH levels. Choice C, 11β-hydroxylase activity, is incorrect as licorice does not impact this enzyme directly. Choice D, glucocorticoid transferase, is also incorrect as licorice does not affect this enzyme's activity.