What are building blocks?

• A. We Use Basic Reflexes to Create More Complex Movements
• B. Components of The Central Nervous System
• C. Short-Term Memory Traces
• D. Sensory Receptors Only

Answer: (A)

Building blocks are the basic reflexes—the simplest, automatic movement responses to a stimulus—that you can combine, scale, and adapt to produce more complex actions. These reflexes give the nervous system a ready-made set of motor units: quick stretch triggers a contraction, a painful stimulus triggers withdrawal, and so on. By linking and modulating these units, higher brain centers sculpt them into coordinated patterns, enabling smooth, purposeful movements like reaching, walking, or manipulating objects. With practice and experience, these reflex-based units are refined and integrated with voluntary control, so complex actions emerge from simpler, repeatable responses rather than from random muscle activity. The other options describe parts or aspects of the system that aren’t the starting, building-block units of movement.