ABSTRACT
As living systems, people exist, develop, and function through three types of environmental transactions: material, energy, and informational. Energy transactions occur when people act to physically influence their relationships with the environment through motor behaviors such as walking, swimming, and manipulating objects. The skeletal-muscle structures and functions provide the basis for such energy transactions. Material and informational transactions also utilize energy transactions. Coordinating components are organized to produce a movement that has “the homogeneity, integration, and structural unity” essential for effective environmental transactions. The skin, the ingestion- digestion-elimination system, and the respiratory structures and functions make such material transactions possible. The structure of muscles illustrates again Mother Nature’s use of hierarchical organization. Evolution organized spinal reflexes into larger units, and in humans there are spinal organizations that can generate locomotion movements when stimulated, even if separated from the brain. Complex action patterns are produced by the organization of component coordinative structures.
