Nokea
Chemical substances secreted by cells into the extracellular fluids that regulate the metabolic function of other cells in the body are called ________.
- A. enzymes
- B. antibodies
- C. proteins
- D. hormones
Correct Answer: D
Rationale: The correct answer is D: hormones. Hormones are chemical substances secreted by cells into extracellular fluids to regulate metabolic functions in other cells. They act as messengers, traveling through the bloodstream to target tissues. Enzymes (A) are catalysts that accelerate chemical reactions. Antibodies (B) are proteins produced by the immune system to neutralize pathogens. Proteins (C) are essential macromolecules for various cellular functions but do not specifically regulate metabolic functions in other cells like hormones do.
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How much gastric juice is secreted daily?
- A. 1.5 litres
- B. 3 litres
- C. 4 litres
Correct Answer: B
Rationale: The correct answer is B (3 litres). The average adult human stomach secretes about 2-3 liters of gastric juice per day. This amount is necessary for the effective digestion of food, as gastric juice contains hydrochloric acid, enzymes, and mucus. Option A (1.5 litres) is too low for daily gastric juice secretion. Option C (4 litres) is too high and could lead to hypersecretion or other digestive issues. Option D is incomplete and does not provide a valid answer. Therefore, option B is the most accurate in reflecting the average daily secretion of gastric juice.
Mr. D, a 60-year-old male with hypothyroidism, is being discharged on levothyroxine therapy. Which of the following symptoms would indicate that he needs immediate follow-up care?
- A. Dry skin
- B. Cold intolerance
- C. Chest pain
- D. Constipation
Correct Answer: C
Rationale: Chest pain could be a sign of angina or other cardiac issues, and it warrants immediate evaluation in a patient with hypothyroidism, especially if on thyroid hormone replacement therapy.
Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference?
- A. It causes positive feedback.
- B. It does not require a second messenger to effect a response.
- C. It is very specific in the cell type it targets.
- D. It is a stimulant of cellular metabolism and targets all cells.
Correct Answer: B
Rationale: The correct answer is B: Thyroxine does not require a second messenger to effect a response. Thyroxine is a non-peptide hormone derived from the amino acid tyrosine, not a peptide hormone. It acts directly on the cell by binding to nuclear receptors, which then bind to specific regions of DNA to regulate gene expression. This mechanism is different from peptide hormones, which typically require second messengers like cAMP or calcium to transmit their signal inside the cell. Therefore, choice B is correct. Choices A, C, and D are incorrect because thyroxine does not cause positive feedback, is not highly specific in cell targeting, and does not target all cells for cellular metabolism stimulation.
A nurse collaborates with assistive personnel (AP) to provide care for a client who is prescribed a 24-hour urine specimen collection. Which statement would the nurse include when teaching the AP about this activity?
- A. Note the time of the client’s first void and collect urine for 24 hours.
- B. Add the preservative to the container at the end of the test.
- C. Start the collection by saving the first urine of the morning.
- D. It is okay if one urine sample during the 24 hours is not collected.
Correct Answer: A
Rationale: The correct answer is A: Note the time of the client's first void and collect urine for 24 hours. This is correct because for a 24-hour urine specimen collection, it is essential to start by noting the exact time of the first void and then collect all subsequent urine voided over the next 24 hours, including the final void at the same time the collection started. This ensures accurate measurement of substances in the urine over a full 24-hour period.
Choice B is incorrect because the preservative should be added to the container at the beginning, not the end, to maintain the integrity of the specimen. Choice C is incorrect because the 24-hour collection starts with the first void, not the first morning urine. Choice D is incorrect as missing even one urine sample during the 24-hour collection can compromise the accuracy of the results.
How many hormones are produced by the posterior pituitary?
- B. 1
- C. 2
- D. 6
Correct Answer: C
Rationale: The correct answer is C: 2. The posterior pituitary produces two hormones: oxytocin and vasopressin. Oxytocin is involved in childbirth and breastfeeding, while vasopressin helps regulate water balance in the body. Option A is incorrect because the posterior pituitary does produce hormones. Option B is incorrect as there are two hormones produced, not just one. Option D is incorrect as the posterior pituitary does not produce six hormones. In summary, the posterior pituitary gland produces two hormones, making option C the correct answer.