Nokea
Pituitary Gland, Which is Also the Master Endocrine Gland Is Controlled by Which of the Following?
- A. Thyroid
- B. Hypothalamus
- C. Pineal gland
- D. None of the above
Correct Answer: B
Rationale: The correct answer is B: Hypothalamus. The hypothalamus controls the pituitary gland by releasing hormones that stimulate or inhibit pituitary hormone production. This relationship is known as the hypothalamic-pituitary axis. The hypothalamus is considered the master controller of the endocrine system, making it the correct choice.
A: Thyroid - The thyroid gland is not directly responsible for controlling the pituitary gland. It is a separate endocrine gland that produces its own hormones.
C: Pineal gland - The pineal gland primarily regulates the sleep-wake cycle and produces melatonin. It does not play a direct role in controlling the pituitary gland.
D: None of the above - This is incorrect as the hypothalamus does indeed control the pituitary gland.
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Which of these is not an endocrine gland?
- A. Pancreas.
- B. Testes.
- C. Salivary gland.
- D. Parathyroid.
Correct Answer: C
Rationale: The correct answer is C, the salivary gland. The salivary gland is not an endocrine gland because it secretes saliva directly into the oral cavity, rather than into the bloodstream like endocrine glands. The pancreas (A) secretes hormones such as insulin and glucagon into the bloodstream. The testes (B) produce hormones like testosterone that are released into the bloodstream. The parathyroid (D) gland secretes parathyroid hormone directly into the bloodstream to regulate calcium levels. In summary, the salivary gland is not considered an endocrine gland because it does not secrete hormones directly into the bloodstream for systemic effects.
Tropic hormones ________.
- A. include ACTH and TSH
- B. do not regulate the function of other endocrine glands
- C. exert their effects on cells by direct gene activation
- D. include GH and PRL
Correct Answer: A
Rationale: The correct answer is A because tropic hormones are hormones that regulate the function of other endocrine glands, such as ACTH (adrenocorticotropic hormone) and TSH (thyroid-stimulating hormone). These hormones stimulate the target glands to release their own hormones. Choice B is incorrect because tropic hormones specifically regulate other endocrine glands. Choice C is incorrect because tropic hormones typically exert their effects by binding to specific receptors on target cells, rather than directly activating genes. Choice D is incorrect because GH (growth hormone) and PRL (prolactin) are not tropic hormones as they do not directly regulate the function of other endocrine glands.
Abrupt, sudden withdrawal of prednisone (cortisol) is most likely to cause:
- A. Cushing syndrome.
- B. hypocalcemic tetany.
- C. diabetes insipidus.
- D. acute adrenal insufficiency.
Correct Answer: D
Rationale: The correct answer is D: acute adrenal insufficiency. Abrupt withdrawal of prednisone can lead to adrenal insufficiency due to suppression of the adrenal glands' natural cortisol production. This can result in symptoms such as fatigue, weakness, abdominal pain, and low blood pressure. Cushing syndrome (choice A) is caused by excessive cortisol, hypocalcemic tetany (choice B) is due to low calcium levels, and diabetes insipidus (choice C) is a disorder of water balance regulation, not related to prednisone withdrawal.
Treatment of acute organophosphorus poisoning includes all of the following EXCEPT:
- A. Intravenous atropine
- B. Decontamination
- C. Artificial respiration and aspiration of secretions
- D. Intravenous methacholine
Correct Answer: D
Rationale: The correct answer is D: Intravenous methacholine. Methacholine is a parasympathomimetic drug that would worsen the symptoms of organophosphorus poisoning by further stimulating the cholinergic receptors. Intravenous atropine is used to counteract the excessive cholinergic stimulation. Decontamination is crucial to remove any remaining poison from the skin or gastrointestinal tract. Artificial respiration and aspiration of secretions help manage respiratory distress caused by the poisoning.
Intravenous administration of epinephrine to a patient results in a severe decrease in diastolic pressure and an increase in cardiac output. Which of the following drugs might the patient have previously taken that could account for this unexpected effect?
- A. Propranolol
- B. Atropine
- C. Phenylephrine
- D. Prazosin
Correct Answer: D
Rationale: The correct answer is D: Prazosin. Prazosin is an alpha-1 adrenergic receptor antagonist, which blocks the vasoconstrictor effect of catecholamines like epinephrine, leading to vasodilation and a decrease in diastolic pressure. The unexpected effect of a decrease in diastolic pressure and an increase in cardiac output after epinephrine administration suggests that the patient might have taken a drug that blocks alpha-1 receptors. Propranolol (A) is a beta-blocker, which would not cause this effect. Atropine (B) is a muscarinic receptor antagonist and would not explain the observed effects. Phenylephrine (C) is an alpha-1 agonist, so it would not result in the described response. Therefore, Prazosin (D) is the most likely drug the patient previously took to account for the unexpected effects of epinephrine administration.