A client with diabetes mellitus asks the nurse how insulin injections help to control this disease. The nurse's best response is that the hormone insulin acts to lower blood glucose by:

Correct Answer: A

Rationale: Insulin, from pancreatic beta cells, lowers blood glucose by transporting glucose into cells (via GLUT4 receptors), promoting storage as glycogen and fat. Glycogenolysis (glucose from glycogen) and gluconeogenesis (new glucose synthesis) raise glucose, glucagon's actions. Liver glucose release counters insulin insulin inhibits it. Glucose uptake distinguishes insulin's role, key to diabetes management, restoring cellular access lost in type I or resisted in type II, unlike glucose-mobilizing processes.

Correct Answer: B

Rationale: Cushing's disease results from excess cortisol, often from pituitary ACTH overproduction, causing weight gain, hypertension, and bone loss. Low cortisol (Addison's) or aldosterone imbalances (Conn's syndrome) differ. High cortisol's systemic effects distinguish Cushing's, critical for diagnosis, contrasting with deficiencies or mineralocorticoid issues.

Correct Answer: B

Rationale: Atrial natriuretic peptide (ANP), from atrial walls, reduces blood volume/pressure by promoting sodium/water excretion. Cholecystokinin aids digestion, renin (kidneys) raises pressure, calcitriol (vitamin D) manages calcium. ANP's atrial origin distinguishes it, vital for cardiovascular homeostasis, contrasting with digestive or renal hormones.

Correct Answer: C

Rationale: TSH (thyroid-stimulating hormone) from the anterior pituitary stimulates thyroid hormone release, regulating metabolism. ADH (vasopressin) and oxytocin, made in the hypothalamus, are stored/released by the posterior pituitary, managing water and lactation. Cortisol, an adrenal cortex glucocorticoid, responds to anterior pituitary ACTH, not a pituitary hormone itself. TSH's anterior origin and tropic role distinguish it, essential for pituitary-thyroid axis, unlike posterior or target gland products.

Correct Answer: C

Rationale: Mineralocorticoids, primarily aldosterone, are synthesized in the adrenal cortex's zona glomerulosa, regulating sodium/potassium balance and blood pressure. Parafollicular cells (thyroid C-cells) produce calcitonin for calcium, not mineralocorticoids. Zona reticularis and fasciculata collaborate reticularis makes androgens, fasciculata glucocorticoids (e.g., cortisol), not mineralocorticoids, though some overlap exists. Zona glomerulosa's outer-layer specificity for aldosterone distinguishes it, critical for electrolyte homeostasis, unlike thyroid or other adrenal zones' roles.