The signals that your brain uses to drive behavior are delivered to other parts of the body by electrical highways called nerves. Nerves are groups of axons, bundled together like a cord. The above image is a cross section of the sciatic nerve in a mouse, with individual cell nuclei in blue. The sciatic nerve begins in the lower spinal cord and has branches that stretch down to the toes. It contains both sensory and motor axons, allowing you to flex your legs and feel the ground beneath your feet.
Michael W. Richardson
Michael W. Richardson is a writer and editor based in Brooklyn, New York, covering topics ranging from the brain and behavior to the environment.
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