Nerves:

Nerves carry electrical impulses between brain and body, allowing us to feel sensations (sensory), move our muscles (motor), and maintain such functions as breathing, sweating, or digesting (autonomic). Nerves can be from a dozen to a million nerve fibers (axons) — long and thin tree-like extensions of individual nerve cells (neurons), bundled up together in connective tissue (myelin sheath). Nerves are the nervous system’s basic building blocks, and neurons are the nerve’s building blocks. The brain contains billions of nerves, including neurons, glial cells (provide structure in the brain), and cranial nerves (from the brain, affecting head and neck). Nerves are in patterns that coordinate thought, emotion, behavior, movement, and sensation. A complex highway system of nerves allows communication in seconds.