Biology Regents Practice Exam 2025 – The All-in-One Guide to Master Your Regents!

The nervous system plays a critical role in responding to stimuli by transmitting signals that facilitate appropriate responses. When a stimulus is detected—whether it's something external like heat, light, or a sound, or internal signals like hunger or pain—sensory neurons relay this information to the brain or spinal cord. The central nervous system then processes these signals, determining the best course of action.

Motor neurons transmit the processed information back to various body parts to elicit responses, such as moving a muscle or activating a gland. This rapid communication network allows organisms to react swiftly and effectively to their environment, ensuring survival and adaptation.

By focusing on how it transmits signals and coordinates responses, it becomes clear that the nervous system is essential for immediate reactions to changes, distinguishing this role from functions such as regulating hormonal balance, producing energy, or maintaining homeostasis, which may involve longer-term processes.