Description of the nervous system
"Nerves are cylindrical bundles of fibers that start at the brain and central cord and branch out to every other part of the body, according to the University of Michigan Medical School.
Neurons send signals to other cells through thin fibers called axons, which cause chemicals known as neurotransmitters to be released at junctions called synapses, the NIH noted. A synapse gives a command to the cell and the entire communication process typically takes only a fraction of a millisecond.
Sensory neurons react to physical stimuli such as light, sound and touch and send feedback to the central nervous system about the body’s surrounding environment, according to the American Psychological Association. Motor neurons, located in the central nervous system or in peripheral ganglia, transmit signals to activate the muscles or glands.
Glial cells, derived from the Greek word for "glue," are specialized cells that support, protect or nourish nerve cells, according to the National Institute on Aging."