Nokea
Tropic hormones:
- A. stimulate the pineal gland to secrete hormones
- B. stimulate the thymus gland to secrete hormones
- C. stimulate other endocrine glands to secrete hormones
- D. stimulate nervous tissue
Correct Answer: C
Rationale: The correct answer is C: Tropic hormones stimulate other endocrine glands to secrete hormones. Tropic hormones are released from the anterior pituitary gland and act on target glands to regulate the secretion of specific hormones. They help maintain homeostasis by controlling hormone levels in the body. Choices A and B are incorrect because tropic hormones do not target the pineal gland or thymus gland. Choice D is incorrect because tropic hormones primarily target endocrine glands, not nervous tissue. In summary, tropic hormones play a key role in regulating hormone production in other endocrine glands, making choice C the correct answer.
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When blood calcium levels are high, ____ is released from the thyroid gland to deposit the excess calcium into the bones.
- A. parathyroid hormone
- B. calcitonin
- C. oxytocin
- D. glucagon
Correct Answer: B
Rationale: Calcitonin is the correct answer because it is released from the thyroid gland in response to high blood calcium levels to deposit the excess calcium into the bones, decreasing blood calcium levels. Parathyroid hormone (A) works in the opposite way, increasing blood calcium levels by releasing calcium from bones. Oxytocin (C) is a hormone involved in labor and breastfeeding, not calcium regulation. Glucagon (D) is released from the pancreas to increase blood glucose levels, not calcium levels. Therefore, calcitonin is the most suitable choice for regulating high blood calcium levels by promoting calcium deposition in the bones.
How is hormone secretion regulated?
- A. by the nervous system
- B. by other hormones
- C. by changes in blood composition
- D. all of the above
Correct Answer: D
Rationale: The correct answer is D because hormone secretion is regulated by various factors. The nervous system can directly stimulate or inhibit hormone release. Other hormones can act as signals to trigger or suppress the secretion of specific hormones. Changes in blood composition, such as glucose levels or electrolyte concentrations, can also influence hormone production and release. Therefore, all of the options play a role in regulating hormone secretion, making choice D the correct answer.
The most important regulator of electrolyte concentrations in extracellular fluids is ________.
- A. insulin
- B. aldosterone
- C. glucagon
- D. cortisol
Correct Answer: B
Rationale: The correct answer is B: aldosterone. Aldosterone is a hormone produced by the adrenal glands that plays a key role in regulating electrolyte concentrations in extracellular fluids. It specifically acts on the kidneys to increase the reabsorption of sodium and water while promoting the excretion of potassium. This helps to maintain the balance of electrolytes in the body. Insulin, glucagon, and cortisol do not directly regulate electrolyte concentrations in extracellular fluids. Insulin regulates blood sugar levels, glucagon regulates glucose release from the liver, and cortisol is involved in stress response and metabolism. Therefore, aldosterone is the most important regulator of electrolyte concentrations in extracellular fluids.
Which one of the following drugs can trigger severe bronchospasm in a patient who has asthma?
- A. Atropine
- B. Isoproterenol
- C. Phenylephrine
- D. Propranolol
Correct Answer: D
Rationale: The correct answer is D: Propranolol. Propranolol is a non-selective beta-blocker that can trigger severe bronchospasm in patients with asthma by blocking beta-2 receptors in the lungs, leading to bronchoconstriction. Atropine (A) is an anticholinergic drug that dilates the airways. Isoproterenol (B) is a beta-agonist that relaxes the airway smooth muscles. Phenylephrine (C) is a sympathomimetic drug that constricts blood vessels, not airways.
Gastrin secretion is stimulated by all but:
- A. luminal peptides
- B. vagal discharge
- C. luminal acid
- D. phenylalanine
Correct Answer: C
Rationale: Rationale: Gastrin secretion is primarily stimulated by luminal peptides and vagal discharge, which promote gastric acid secretion. Luminal acid, on the other hand, inhibits gastrin release as it acts as a negative feedback mechanism to regulate acid production. Phenylalanine does not directly stimulate gastrin secretion. Therefore, the correct answer is C as luminal acid inhibits, not stimulates, gastrin release. The other choices are incorrect because luminal peptides and vagal discharge are known stimulants of gastrin secretion, while phenylalanine does not have a direct effect on gastrin release.