ACE Personal Trainer Practice Exam

The primary role of the nervous system in relation to the body is to collect and analyze information about the external environment. This encompasses sensory input, processing information, and responding to stimuli, which is essential for survival and interaction with the surroundings. The nervous system receives signals from sensory organs, integrates this information, and coordinates appropriate responses through motor functions.

While controlling muscle contractions and movements, regulating internal body temperature, and aiding in digestion are important functions, they are more specific roles of particular systems in the body. For instance, muscle control is primarily a function of the muscular system, temperature regulation involves the endocrine and integumentary systems, and digestion is the duty of the digestive system. The broad, overarching role of the nervous system is to serve as the command center for receiving sensory input and orchestrating an appropriate response, making option B the most accurate choice.