Most hormones belong to what chemical classes?

Correct Answer: B

Rationale: Most hormones are peptides (e.g., insulin, ACTH) or steroids (e.g., cortisol, estrogen), derived from amino acids or cholesterol, respectively dominant classes. Amines (e.g., epinephrine) exist but are fewer, not paired with sodium (an ion). Glucose isn't a hormone class metabolic substrate. Sodium isn't hormonal electrolyte. Peptides and steroids distinguish endocrine diversity, key to their synthesis and action, unlike minor or non-hormonal pairs.

Correct Answer: C

Rationale: ADH deficiency causes diabetes insipidus polyuria/polydipsia from poor water reabsorption, dilute urine. Diabetes mellitus is insulin-related, glucose-driven. Uterine contractions tie to oxytocin, not ADH. Decreased urine opposes DI volume rises. DI's water loss distinguishes it, key to ADH's role, unlike glucose, contraction, or retention conditions.

Correct Answer: B

Rationale: Simple goiter (thyroid enlargement) from iodine deficiency is prevented by dietary iodine enables T3/T4 synthesis, avoiding compensatory growth. Antibiotics treat infection, not deficiency. Surgery removes goiter, not prevents. Hormone therapy (e.g., levothyroxine) treats hypothyroidism, not root cause. Iodine addition distinguishes prevention, key to thyroid health, unlike infection, surgical, or replacement approaches.

Correct Answer: C

Rationale: Adrenal medulla, inner gland portion, is nervously controlled (sympathetic), producing epinephrine/norepinephrine fight-or-flight. Glucose/mineral regulation is adrenal cortex (cortisol, aldosterone), not medulla distinct roles. Medulla's neural-catecholamine function distinguishes it, key to acute stress, unlike cortex's metabolic/electrolyte tasks.

Correct Answer: A

Rationale: Adrenal cortex hyposecretion (low cortisol/aldosterone) causes Addison's fatigue, low BP, hyperpigmentation from ACTH rise. Diabetes mellitus is pancreatic glucose issue. Cushing's is cortisol excess opposite. Cretinism is neonatal hypothyroidism growth/mental delay. Addison's adrenal failure distinguishes it, key to cortex insufficiency, unlike glucose, excess, or thyroid conditions.