Which of the following is NOT true of Cushing syndrome?

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: 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.

Correct Answer: C

Rationale: The correct answer is C because lipid-soluble hormones can freely diffuse through cell membranes to interact with intracellular receptors, leading to changes in gene expression. This mechanism is characteristic of lipid-soluble hormones, such as steroid hormones. Choice A is incorrect because lipid-soluble hormones are not constantly produced in the anterior pituitary gland. Choice B is incorrect as lipid-soluble hormones are hydrophobic, not hydrophilic, and are often transported bound to carrier proteins in the blood. Choice D is incorrect because lipid-soluble hormones are not formed from amino acids; rather, they are derived from cholesterol or similar compounds.

Correct Answer: D

Rationale: The correct answer is D, submandibular glands, as they produce the majority of salivary volume. These glands are the largest of the major salivary glands and secrete saliva rich in enzymes and mucin, contributing significantly to the total saliva volume. The lingual glands (A) are minor salivary glands located in the tongue and contribute a small portion of saliva. The sublingual glands (B) are also minor salivary glands located beneath the tongue, producing a smaller volume compared to the submandibular glands. The parotid glands (C) are another major salivary gland, but they produce a lesser volume of saliva compared to the submandibular glands.

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.