Nokea
Insulin, a small (51-amino-acid) protein, is synthesized by the beta cells of the pancreas. This hormone is released ________.
- A. in excessive amounts in obese people
- B. in response to severe physical stress (i.e., a ten-mile run)
- C. when the bodyʹs glucose level rises
- D. when the bodyʹs glucose level drops
Correct Answer: C
Rationale: The correct answer is C because insulin is released when the body's glucose level rises. This is a key function of insulin to regulate blood sugar levels. When glucose levels increase after a meal, beta cells release insulin to help cells absorb and use glucose for energy. This process helps to maintain blood sugar within a healthy range.
Choice A is incorrect because insulin release is not necessarily excessive in obese people, but rather it can be impaired due to insulin resistance. Choice B is incorrect because insulin is typically released in response to high blood sugar levels, not physical stress. Choice D is incorrect because insulin is released when blood sugar levels drop too low, not rise.
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Which of the following is an anterior pituitary hormone?
- A. ADH
- B. oxytocin
- C. TSH
- D. cortisol
Correct Answer: C
Rationale: The correct answer is C: TSH (Thyroid Stimulating Hormone). The anterior pituitary gland secretes TSH, which stimulates the thyroid gland to produce thyroid hormones. This is a key hormone involved in regulating metabolism.
A: ADH (Antidiuretic Hormone) is produced by the posterior pituitary gland.
B: Oxytocin is also produced by the posterior pituitary gland and is involved in uterine contractions and lactation.
D: Cortisol is produced by the adrenal glands, not the pituitary gland.
In summary, TSH is the correct answer as it is the only hormone listed that is produced by the anterior pituitary gland.
Which of the following are incorrectly paired?
- A. Gluconeogenesis : Cortisol
- B. Free fatty acid mobilization : Dehydroepiandrosterone
- C. Muscle glycogenolysis : Epinephrine
- D. Kaliuresis : Aldosterone
Correct Answer: B
Rationale: The correct answer is B because free fatty acid mobilization is primarily regulated by cortisol, not dehydroepiandrosterone. Cortisol promotes lipolysis and stimulates the release of free fatty acids from adipose tissue. Dehydroepiandrosterone is a precursor hormone mainly involved in sex hormone production and has minimal effects on free fatty acid mobilization. Choices A, C, and D are correctly paired as gluconeogenesis is stimulated by cortisol, muscle glycogenolysis is regulated by epinephrine, and kaliuresis is induced by aldosterone.
Exemplify hormones secreted by the anterior pituitary.
- A. anti-diuretic hormone and oxytocin
- B. ACTH and insulin
- C. growth hormone and LH
- D. thyroxine and cortisol
Correct Answer: C
Rationale: The correct answer is C: growth hormone and LH. The anterior pituitary gland secretes these hormones. Growth hormone regulates growth, metabolism, and body composition, while LH (luteinizing hormone) plays a role in reproductive function.
A: Anti-diuretic hormone and oxytocin are produced by the posterior pituitary gland.
B: ACTH (adrenocorticotropic hormone) is secreted by the anterior pituitary, but insulin is produced by the pancreas.
D: Thyroxine is released by the thyroid gland, and cortisol is produced by the adrenal glands, not the anterior pituitary.
The Action of Parathormone in the Human Body
- A. Decreases blood sodium level
- B. Increases blood sodium level
- C. Decreases blood calcium level
- D. Increases blood calcium level
Correct Answer: D
Rationale: The correct answer is D: Increases blood calcium level. Parathormone is released by the parathyroid glands in response to low blood calcium levels. It acts to increase blood calcium levels by stimulating the release of calcium from bones, increasing calcium absorption in the intestines, and promoting calcium reabsorption in the kidneys. This helps to maintain proper calcium levels in the body. Choices A, B, and C are incorrect because parathormone does not have any direct effect on blood sodium levels and actually works to increase, not decrease, blood calcium levels.
Which of the following is least characteristic of the function of insulin?
- A. Increases glucose transport (into the cell).
- B. Suppresses gluconeogenesis.
- C. Lowers blood glucose.
- D. Increases the generation of ketone bodies.
Correct Answer: D
Rationale: The correct answer is D because insulin does not increase the generation of ketone bodies. Insulin actually inhibits ketogenesis by promoting glucose utilization and storage, preventing the breakdown of fats for energy. A, B, and C are all characteristics of insulin's function: A) Insulin increases glucose transport into the cell to lower blood glucose levels; B) It suppresses gluconeogenesis, the production of new glucose in the liver; C) Insulin lowers blood glucose levels by promoting the uptake and storage of glucose in cells.