Insulin Facilitates Glucose Uptake to Prevent Glucosuria

Steps:

• In diabetes, high blood glucose exceeds kidney reabsorption capacity, leading to glucose in urine (glucosuria).
• Insulin binds to cell receptors, activating glucose transporters (GLUT4) to move glucose into cells.
• This lowers blood glucose levels below the renal threshold (about 180 mg/dL).
• Reduced blood glucose prevents spillover into urine.

Why B is correct:

• Insulin promotes glucose uptake into cells by stimulating GLUT4 translocation, as defined in cellular physiology, reducing blood glucose and avoiding renal filtration excess.

Why the others are wrong:

• A: Insulin does not increase urine water; it indirectly reduces osmotic diuresis by lowering glucose.
• C: Insulin acts post-digestion; it does not prevent starch breakdown into glucose in the gut.
• D: Insulin has no direct role in raising blood pressure; it primarily regulates metabolism.

Final answer: B