The nervous system in humans work together to collect information about the external environment because they consist of the brain, spinal cords and neurons. They collect information from external environment and those information travels through neurons from sense organs like eyes, ears, skin e.t.c as a form of electrical impulses. When they get to the end of the neuron, a chemical called neurotransmitters are released which travels across the cells and send it to the brain, the brain then process it and interprete the signals and respond to it as stimulus.
