Nokea
Most hormones of the endocrine system are regulated by a:
- A. Negative feedback mechanism.
- B. Positive feedback mechanism.
- C. Hormone-receptor complex.
- D. Hormone-gene complex.
Correct Answer: A
Rationale: The correct answer is A: Negative feedback mechanism. This is because most hormones in the endocrine system are regulated by a negative feedback loop, where the release of a hormone is inhibited once a certain level of that hormone is reached in the body. This helps maintain homeostasis.
Incorrect choices:
B: Positive feedback mechanism - This is less common in hormone regulation as it leads to amplification of a response rather than maintaining balance.
C: Hormone-receptor complex - While hormones bind to receptors to exert their effects, this is not the primary mechanism of hormone regulation.
D: Hormone-gene complex - While hormones can affect gene expression, this is not the primary mechanism of hormone regulation in the endocrine system.
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Which is NOT an action of CCK?
- A. gallbladder contraction
- B. increased gastric motility and emptying
- C. glucagon secretion
- D. secretion of pancreatic juice
Correct Answer: B
Rationale: The correct answer is B: increased gastric motility and emptying. CCK, or cholecystokinin, is a hormone released by the small intestine in response to the presence of fats. Its main actions include stimulating gallbladder contraction (A) to release bile for fat digestion, triggering the secretion of pancreatic juice (D) containing digestive enzymes, and inhibiting gastric motility and emptying. Therefore, increased gastric motility and emptying (choice B) is NOT an action of CCK. This is because CCK acts to slow down gastric emptying to allow for effective digestion of fats in the small intestine. Choices A, C, and D are all correct actions of CCK based on its role in the digestive process.
Ipratropium is a synthetic bronchodilator atropine substitute administered by:
- A. Oral route
- B. Intravenous injection
- C. Subcutaneous injection
- D. Inhalation
Correct Answer: D
Rationale: The correct answer is D: Inhalation. Ipratropium is a bronchodilator used to treat conditions like asthma and chronic obstructive pulmonary disease (COPD). Inhalation allows direct delivery to the lungs, where it acts locally to relax the smooth muscle and dilate the airways, providing rapid relief of bronchospasm. Oral route (A) would result in poor absorption and systemic side effects. Intravenous (B) and subcutaneous (C) injections are not preferred due to the risk of systemic effects and lack of targeted action. Thus, inhalation is the most effective and appropriate route for ipratropium administration.
Which colour change is observed when water is added to anhydrous cobalt(II) chloride?
- A. blue to white
- B. blue to pink
- C. white to blue
- D. pink to blue
Correct Answer: B
Rationale: The correct answer is B: blue to pink. Anhydrous cobalt(II) chloride is blue, and when water is added, it forms a pink hexahydrate complex. This color change occurs because water molecules replace the chloride ions in the crystal lattice, resulting in the formation of the pink complex. Choice A (blue to white) is incorrect because the addition of water does not change the color to white. Choice C (white to blue) is incorrect as anhydrous cobalt(II) chloride is blue to begin with. Choice D (pink to blue) is incorrect as the addition of water causes the color change from blue to pink, not the other way around.
Which of the following organs is considered a neuroendocrine organ?
- A. pituitary
- B. hypothalamus
- C. pancreas
- D. adrenal cortex
Correct Answer: B
Rationale: The correct answer is B: hypothalamus. The hypothalamus is considered a neuroendocrine organ because it produces and releases hormones that regulate the pituitary gland's hormonal secretion. It acts as a bridge between the nervous system and the endocrine system, controlling various physiological processes. The pituitary gland (choice A) is a master endocrine gland, not a neuroendocrine organ. The pancreas (choice C) is an exocrine and endocrine gland involved in blood sugar regulation. The adrenal cortex (choice D) is part of the adrenal glands responsible for producing steroid hormones, not considered a neuroendocrine organ.
In evaluating the effectiveness of a new insulin dosage for a diabetic patient, the nurse would
- A. check the urine for sugar and acetone
- B. collect a 24-hour urine specimen for acetone determination
- C. weigh the patient daily
- D. rotate the site of injection
Correct Answer: A
Rationale: Checking urine for sugar and acetone provides a quick measure of whether the insulin dosage is adequate in controlling blood glucose levels.