Which of the following is an example of negative feedback in physiological regulation?

• A. Shivering when cold
• B. Positive feedback during childbirth
• C. Blood clotting cascade
• D. Release of hormones to amplify a rapid response

Answer: (A)

Negative feedback returns a system toward its set point by counteracting the initial change. When cold, detectors trigger shivering to generate heat, raising body temperature back toward normal and then stopping once warmth is restored. That reversal of the initial deviation exemplifies a classic negative feedback loop that maintains homeostasis. The other options describe processes that amplify a condition rather than oppose it—positive feedback during childbirth, the blood clotting cascade, and hormones that boost a rapid response all push the system further from the starting state rather than bringing it back to balance.