Final answer:
The nervous system performs three main functions: sensation, integration, and motor response.
Step-by-step explanation:
The nervous system performs three main functions: sensation, integration, and motor response. Sensation involves receiving information from the environment around us, such as through the senses. Integration combines sensory input with memories, emotions, and learning to produce a response. Motor response refers to the generation of a response, such as movement or a physiological change.