The following effects of thyroid hormone include all of the following except

Correct Answer: C

Rationale: Thyroid hormones (T3/T4) boost Na/K ATPase (metabolism), nitrogen excretion (catabolism), and α-myosin chains (cardiac efficiency), but don't directly increase catecholamine levels they sensitize tissues to them via β-receptors. Catecholamine production is adrenal, not thyroid-driven. Exclusion of catecholamine increase distinguishes it, key to thyroid's calorigenic scope, unlike metabolic or cardiac effects.

Correct Answer: B

Rationale: Somatostatin inhibits insulin secretion from β-cells, reducing glucose uptake regulatory role. Insulin promotes protein synthesis, not catabolism anabolic. Phenytoin doesn't notably stimulate insulin glucose metabolism does. Insulin increases K⁺ uptake with glucose, not decreases. Somatostatin's inhibition distinguishes it, key to pancreatic regulation, unlike anabolic, drug, or K⁺ errors.

Correct Answer: B

Rationale: Adrenocorticotropic hormone (ACTH) from the anterior pituitary stimulates cortisol secretion from the adrenal cortex, key to stress response not LH, prolactin, IGFs (GH mediators), or MSH. ACTH's role in the HPA axis distinguishes it, critical for glucocorticoid regulation, contrasting with unrelated hormones.

Correct Answer: D

Rationale: T3 and T4 synthesis involves iodide trapping, oxidation to iodine, tyrosine iodination, and coupling not calcitonin synthesis, which occurs in separate thyroid C-cells for calcium regulation. This exclusion distinguishes thyroid hormone production, essential for metabolism, from unrelated calcitonin processes.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.