• Entire nerve apparatus; in higher animals it is composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses.
  CRISP Thesaurus
  National Institutes of Health, 2006
• The entire nerve apparatus, composed of a central part, the brain and spinal cord, and a peripheral part, the cranial and spinal nerves, autonomic ganglia, and plexuses. (Stedman, 26th ed)
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021
• The organized network of nerve tissue in the body. It includes the central nervous system (the brain and spinal cord), the peripheral nervous system (nerves that extend from the spinal cord to the rest of the body), and other nerve tissue.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• The nervous system has two distinct parts: the central nervous system (the brain and spinal cord) and the peripheral nervous system (the nerves outside the brain and spinal cord).
  Merck Manuals
  Merck & Co., Inc., 2020
• Human nervous system, system that conducts stimuli from sensory receptors to the brain and spinal cord and conducts impulses back to other parts of the body. As with other higher vertebrates, the human nervous system has two main parts: the central nervous system (the brain and spinal cord) and the...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2020
• Nervous system, organized group of cells specialized for the conduction of electrochemical stimuli from sensory receptors through a network to the site at which a response occurs. All living organisms are able to detect changes within themselves and in their environments. Changes in the external...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2020