A client diagnosed with attention-deficit/hyperactivity disorder (ADHD) is prescribed stimulant medication. The nurse explains that these medications work by:

Correct Answer: B

Rationale: Stimulants improve focus and impulse control in ADHD.

Correct Answer: A

Rationale: Kidneys metabolize insulin; reduced function requires smaller doses.

Correct Answer: D

Rationale: Antidiuretic hormone (ADH) is produced in the hypothalamus (D), specifically in supraoptic and paraventricular nuclei, then stored in the posterior pituitary. Juxtaglomerular cells (A) produce renin, anterior pituitary (B) releases ACTH, and adrenal cortex (C) makes aldosterone, making D correct.

Correct Answer: A

Rationale: The macula densa, part of the distal convoluted tubule, contacts juxtaglomerular cells at the afferent arteriole, forming the JGA to regulate renin (A). This anatomical feature is true, not false (B), making A correct.

Correct Answer: D

Rationale: Na⁺ reabsorption in the PCT uses active transport (D) via Na+/K+ ATPase and Na+/H+ exchangers, not phagocytosis (A), endocytosis (B), or diffusion (C), making D the primary mechanism.