Nokea
A deficiency of dietary iodine:
- A. lowers plasma calcium levels.
- B. causes low blood volume and shock.
- C. decreases the synthesis of calcitonin.
- D. causes a goiter.
Correct Answer: D
Rationale: The correct answer is D because a deficiency of dietary iodine leads to an insufficient production of thyroid hormones, which can result in the enlargement of the thyroid gland, known as a goiter. This is due to the thyroid gland working harder to try to produce more hormones.
A, B, and C are incorrect because a deficiency of dietary iodine does not directly affect plasma calcium levels, blood volume, or the synthesis of calcitonin. These are functions that are primarily regulated by other hormones and factors in the body, not by iodine deficiency.
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Adrenaline is NOT given orally because:
- A. It is inactivated in the gut mucosa
- B. Local vasoconstriction inhibits absorption
- C. It is rapidly inactivated in circulation
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D: All of the above. Adrenaline is not given orally because: A) It is inactivated in the gut mucosa due to enzymatic breakdown, B) Local vasoconstriction inhibits absorption into the bloodstream, and C) It is rapidly inactivated in circulation by enzymes like catechol-O-methyltransferase and monoamine oxidase. Therefore, administering adrenaline orally would result in poor absorption and rapid degradation, making it ineffective.
What is meant by antibiotic resistance?
- A. No bacteria will be killed by any antibiotic.
- B. Only some bacteria will be killed by some antibiotics.
- C. No viruses will be killed by any antibiotic.
- D. Only some viruses will be killed by some antibiotics.
Correct Answer: B
Rationale: The correct answer is B: Only some bacteria will be killed by some antibiotics. Antibiotic resistance refers to the ability of bacteria to survive and grow despite the presence of an antibiotic. This occurs when bacteria evolve and develop mechanisms to defend against antibiotics. It is not accurate to say that no bacteria will be killed by any antibiotic (choice A) as some bacteria may still be susceptible to certain antibiotics. Antibiotics are not effective against viruses, so choice C and D are incorrect. In summary, antibiotic resistance specifically pertains to bacteria developing the ability to survive some antibiotics, making choice B the correct answer.
Which hormones of the adrenal glands supplement the sex hormones from the gonads?
- A. Mineralocorticoids, such as aldosterone
- B. Glucocorticoids, such as cortisol
- C. Gnadocorticoids, such as the androgens
- D. Epinephrine and norepinephrine.
Correct Answer: C
Rationale: The correct answer is C, Gnadocorticoids, such as the androgens. The adrenal glands produce androgens like DHEA which can supplement sex hormones from the gonads. Choice A, mineralocorticoids, control electrolyte and water balance. Choice B, glucocorticoids, regulate metabolism and immune response. Choice D, epinephrine and norepinephrine, are involved in the fight or flight response. Gnadcorticoids, specifically androgens, are the hormones from the adrenal glands that can supplement sex hormones from the gonads, making choice C the correct answer.
Which of the following signals would affect local cells by releasing chemicals into the extracellular fluid?
- A. autocrine
- B. paracrine
- C. endocrine
- D. neural
Correct Answer: B
Rationale: The correct answer is B: paracrine. Paracrine signaling involves the release of signaling molecules into the extracellular fluid to affect nearby target cells. This type of signaling is localized and affects cells within close proximity. Autocrine signaling (A) involves cells releasing signals that act on themselves, endocrine signaling (C) involves signaling molecules being released into the bloodstream to affect distant target cells, and neural signaling (D) involves the transmission of signals through neurons. In this case, paracrine signaling specifically targets local cells by releasing chemicals into the extracellular fluid, making it the correct choice.
Which hormone is most important in insulin secretion?
- A. gastrin
- B. CCK
- C. GIP
- D. secretin
Correct Answer: C
Rationale: The correct answer is C: GIP (glucose-dependent insulinotropic peptide). GIP is an incretin hormone released from the small intestine in response to glucose ingestion, stimulating insulin secretion from pancreatic beta cells. Gastrin (A), CCK (B), and secretin (D) are gastrointestinal hormones that do not directly influence insulin secretion. GIP plays a crucial role in regulating blood sugar levels by promoting insulin release, making it the most important hormone in insulin secretion.