The production and release of hormones caused by a chemical such as calcium is a _____ mechanism.

Correct Answer: A

Rationale: The correct answer is A: humoral. Humoral regulation refers to the control of physiological processes by substances in the blood, such as hormones. In this case, the production and release of hormones in response to a chemical like calcium is an example of humoral mechanism. This choice is correct because it specifically involves the blood-borne substances affecting hormone production. Choices B, C, and D are incorrect because neural regulation (B) involves the nervous system controlling physiological processes, sensory regulation (C) refers to sensory input influencing responses, and hormonal regulation (D) involves feedback loops within the endocrine system, not directly related to blood-borne substances like calcium.

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.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Cushing syndrome is characterized by hypersecretion of adrenal cortex hormones, not hyposecretion. 2. Option D states hyposecretion, which is incorrect for Cushing syndrome. 3. Trunk obesity, moon-shaped face, and alkalosis (basic blood pH) are characteristic features of Cushing syndrome. 4. Thus, option D is the correct answer because it is not a true characteristic of Cushing syndrome. Summary: Option D is incorrect because Cushing syndrome is associated with hypersecretion of adrenal cortex hormones, not hyposecretion. Options A, B, and C are true characteristics of Cushing syndrome, making them incorrect choices.

Correct Answer: C

Rationale: The correct answer is C: Gluconeogenesis is not a function of insulin. Insulin's main role is to lower blood glucose levels by promoting glucose uptake and storage. Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources, such as amino acids and glycerol, to increase blood glucose levels. Insulin inhibits gluconeogenesis by suppressing the enzymes involved in this process. Choices A, B, and D are all functions of insulin: A) Decreasing glycogenolysis - insulin promotes glycogen synthesis by inhibiting glycogen breakdown, B) Lipogenesis - insulin enhances the conversion of excess glucose into fatty acids for storage, and D) Glycogenesis - insulin increases the formation of glycogen from glucose for storage.

Correct Answer: A

Rationale: Aldosterone is the correct answer as it specifically regulates blood sodium and potassium levels by acting on the kidneys to enhance sodium reabsorption and potassium excretion. Cortisol is a stress hormone, not directly involved in electrolyte regulation. Glycogens are stored glucose molecules, not hormones. Pheromones are chemical signals for communication, not involved in electrolyte balance.