Which body system responds to stimuli by activating muscles and glands?

The nervous system is responsible for responding to stimuli by activating muscles and glands. This system is composed of the brain, spinal cord, and a network of nerves that facilitate rapid communication throughout the body. When a stimulus is detected, sensory neurons transmit the information to the central nervous system, where it is processed. The nervous system then coordinates an appropriate response by sending signals through motor neurons to muscles, causing them to contract, or to glands, prompting them to release hormones or other substances.

This quick and precise communication enables the body to react almost instantaneously to environmental changes, such as withdrawing a hand from a hot surface or increasing salivation in response to food. The integration of sensory input and motor output forms the basis of reflexes and many voluntary actions, illustrating the pivotal role of the nervous system in maintaining homeostasis and facilitating interactions with the environment.