Which system is responsible for coordinating body activities through signals?

The nervous system is responsible for coordinating body activities through signals because it consists of a complex network of neurons that transmit electrical impulses throughout the body. This system allows for rapid communication between different parts of the body, enabling organisms to respond quickly to changes in their environment. It detects stimuli, processes information, and controls bodily responses by sending signals to various organs and systems.

Specifically, the nervous system is divided into the central nervous system (the brain and spinal cord) and the peripheral nervous system (nerves that extend throughout the body). This structure is essential for functions such as reflex actions, voluntary movements, and the regulation of internal processes, making it the primary communication system within the body.

In contrast, the circulatory system primarily transports blood and nutrients, the digestive system is focused on breaking down food and absorbing nutrients, and the muscular system is involved in movement and maintaining posture. These systems do not have the direct role of coordinating activities through signals in the same comprehensive and rapid manner as the nervous system does.