Which of the Following Endocrine Glands Contributes to Setting the Body's Biological Clock?
- A. Pituitary gland
- B. Pineal gland
- C. Thymus gland
- D. Adrenal gland
Correct Answer: B
Rationale: The correct answer is B: Pineal gland. The pineal gland secretes melatonin, a hormone that regulates the body's sleep-wake cycle, thus contributing to setting the body's biological clock. This gland responds to light and darkness, helping to synchronize our internal clock with the day-night cycle. The pituitary gland (A) regulates various hormones but not specifically the biological clock. The thymus gland (C) is responsible for immune function, not the biological clock. The adrenal gland (D) secretes hormones related to stress response, not the biological clock. In summary, the pineal gland is key in regulating the body's biological clock through melatonin secretion, making it the correct choice.
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Steroid hormones:
- A. require a second messenger.
- B. are secreted by the adrenal cortex.
- C. are secreted by the posterior pituitary.
- D. are secreted by the pancreas.
Correct Answer: B
Rationale: The correct answer is B: Steroid hormones are secreted by the adrenal cortex. The adrenal cortex is responsible for producing steroid hormones such as cortisol, aldosterone, and sex hormones. This is supported by the understanding of endocrine gland functions. Choices A, C, and D are incorrect because steroid hormones do not require a second messenger, are not secreted by the posterior pituitary, and are not secreted by the pancreas. Understanding the specific glands and their hormone production is crucial in selecting the correct answer.
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 of the following hormones is released from the posterior pituitary gland?
- A. Antidiuretic hormone
- B. Thyroid-stimulating hormone
- C. Parathyroid hormone
- D. Prolactin
Correct Answer: A
Rationale: Antidiuretic hormone (ADH) is released by the posterior pituitary and plays a key role in regulating water balance in the body.
Which of the following is not under the direct control of the pituitary gland?
- A. Adrenal cortical secretion of glucocorticoid
- B. Parathyroid secretion of PTH
- C. Thyroid gland secretion of T3 and T4
- D. Ovarian secretion of estrogen and progesterone
Correct Answer: B
Rationale: The correct answer is B. The pituitary gland does not directly control the parathyroid gland secretion of PTH. The pituitary gland is responsible for secreting hormones that regulate other endocrine glands, such as adrenal cortex (A), thyroid gland (C), and ovaries (D). In contrast, the parathyroid gland is primarily regulated by the calcium levels in the blood, not directly by the pituitary gland. Therefore, choices A, C, and D are incorrect as they are all glands whose secretions are directly controlled by the pituitary gland.
Mr. Weber, an insulin-dependent diabetic, states that in the afternoon he has occasional severe reactions during which he becomes unconscious. In planning his care, which of the following nursing actions is most appropriate?
- A. Placing a tube of commercially prepared glucose paste at his bedside
- B. Administering regular insulin
- C. Checking his level of consciousness every hour
- D. Keeping a supply of orange juice in the refrigerator
Correct Answer: A
Rationale: For a patient with severe hypoglycemic reactions, it's essential to have a quick source of glucose on hand, like glucose paste, to treat unconsciousness from low blood sugar.