Nokea
The endocrine gland responsible for the body’s circadian rhythm is:
- A. Thymus
- B. Pineal
- C. Parathyroid
- D. Pituitary
Correct Answer: B
Rationale: The correct answer is B: Pineal gland. The pineal gland secretes melatonin, a hormone that regulates the body's circadian rhythm. Melatonin helps control the sleep-wake cycle, making the pineal gland crucial for maintaining our internal body clock. The other choices, Thymus, Parathyroid, and Pituitary glands, are not directly involved in regulating circadian rhythms. Thymus is responsible for immune function, Parathyroid regulates calcium levels, and Pituitary gland controls various hormones but not specifically circadian rhythm. Hence, the pineal gland is the correct choice for this question.
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A patient who recently had a calcium oxalate renal stone had a bone density study, which showed a decrease in her bone density. What endocrine problem could this patient have?
- A. SIADH
- B. Cushing syndrome
- C. Hypothyroidism
- D. Hyperparathyroidism
Correct Answer: D
Rationale: Hyperparathyroidism can lead to bone demineralization, which may cause a decrease in bone density, and is often associated with kidney stones.
Jan, an insulin-dependent diabetic, was admitted to the emergency room with hypoglycemia after playing tennis all afternoon. The probable cause of this reaction was
- A. increased exercise level
- B. insufficient insulin dosage
- C. increased food intake
- D. increased glucagon production
Correct Answer: A
Rationale: Increased exercise can cause hypoglycemia in insulin-dependent diabetics by using up glucose in the body more quickly than the insulin can manage.
What is the hormone produced by adipose tissue which signals satiety?
- A. melatonin
- B. leptin
- C. thymosins
- D. glucagons
Correct Answer: B
Rationale: Leptin is the correct answer because it is a hormone produced by adipose tissue that signals satiety to the brain, helping regulate energy balance and food intake. Melatonin is a hormone that regulates sleep-wake cycles, not hunger. Thymosins are involved in immune function. Glucagon is a hormone that increases blood sugar levels, not related to satiety.
The transcription of new messenger RNA is a function of __________.
- A. pancreatic hormones
- B. steroid hormones
- C. catecholamines
- D. pituitary gland hormones
Correct Answer: B
Rationale: The correct answer is B: steroid hormones. Steroid hormones are known to regulate gene expression by binding to specific receptors and influencing transcription processes. They can directly affect the transcription of new messenger RNA in the cell. Pancreatic hormones (A), catecholamines (C), and pituitary gland hormones (D) are not directly involved in the transcription of new messenger RNA. Pancreatic hormones primarily regulate blood sugar levels, catecholamines are involved in the fight-or-flight response, and pituitary gland hormones regulate various functions such as growth, reproduction, and metabolism.
Ritodrine is a drug indicated for suppressing uterine contractions in premature labor. The drug also causes bronchodilation. It has no vasoconstrictor effects, nor any effects on the size of the pupil of the eye. Which of the following is the most likely classification of this drug?
- A. α-adrenergic agonist
- B. Antimuscarinic drug
- C. β-adrenergic agonist
- D. β-adrenergic blocker
Correct Answer: C
Rationale: The correct answer is C: β-adrenergic agonist. Ritodrine is indicated for suppressing uterine contractions, which is a typical effect of β-adrenergic agonists. Bronchodilation is also a known effect of β-adrenergic agonists. Since the drug has no vasoconstrictor effects and does not affect the size of the pupil of the eye, it is unlikely to be an α-adrenergic agonist or an antimuscarinic drug. Additionally, the fact that ritodrine causes bronchodilation further supports its classification as a β-adrenergic agonist.