Which statement best describes a positive feedback loop?

• A. It dampens the response to maintain stability.
• B. It reinforces the original action, increasing the response.
• C. It stops after a single cycle.
• D. It has no effect on physiological processes.

Answer: (B)

Positive feedback loops amplify a change by reinforcing the initial stimulus, driving the system farther from its starting point until a final event completes the process. This is why it’s seen in rapid, decisive outcomes like childbirth, where contractions promote more oxytocin release and stronger contractions until delivery, and in blood clotting, where platelet activation leads to the recruitment of more platelets until a clot forms. So describing it as reinforcing the original action and increasing the response is the best match. The other ideas describe negative feedback (damping to keep things stable), stopping after one cycle (positive feedback typically continues until the outcome is reached), or having no effect on bodily processes (false).