The integrative action of the nervous system involves the coordination of various signals from the body to maintain homeostasis and respond to external stimuli. It processes information received from sensory organs, such as the eyes and ears, and integrates this data to produce appropriate responses. This function is crucial for activities like reflexes and voluntary movements. Additionally, the central nervous system (CNS), which includes the brain and spinal cord, plays a key role in this integration. It interprets sensory information and sends commands to the peripheral nervous system (PNS), which connects the CNS to the rest of the body, ensuring effective communication and response.