Body temperature and blood sugar are regulated by which mechanism?

• A. Negative feedback mechanism
• B. Positive feedback mechanism
• C. Feedforward mechanism
• D. Random oscillations

Answer: (A)

Negative feedback loops regulate body temperature and blood sugar. In these loops, sensors detect a deviation from the normal set point, a control center interprets the signal, and effectors act to counter that change, nudging the value back toward the set point. For temperature, receptors in the skin and the brain monitor heat; the brain then triggers sweating and blood vessel dilation to cool the body or shivering and vessel constriction to warm it, restoring normal temperature. For blood sugar, rise after a meal prompts insulin release, which helps cells take up glucose and stores it, lowering blood sugar; when levels drop, glucagon signals release of glucose from liver stores, raising it back up. This push-pull back toward the set point is characteristic of negative feedback.

Positive feedback would amplify departures from the norm, not maintain stability—examples include certain processes like childbirth or blood clotting, where the response keeps driving change rather than restoring balance. Feedforward mechanisms can anticipate changes and adjust responses ahead of time, but the essential regulation of temperature and glucose under normal conditions is through negative feedback. Random oscillations aren’t a regulatory mechanism.