• A watery fluid that is continuously produced in the CHOROID PLEXUS and circulates around the surface of the BRAIN; SPINAL CORD; and in the CEREBRAL VENTRICLES.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Clear colorless liquid secreted by the choroid plexus of the lateral, third, and fourth ventricles, and contained within the ventricular system of the brain and spinal cord and within the subarachnoid space.
  CRISP Thesaurus
  National Institutes of Health, 2006
• The fluid that flows in and around the hollow spaces of the brain and spinal cord, and between two of the meninges (the thin layers of tissue that cover and protect the brain and spinal cord). CSF is made by tissue called the choroid plexus in the ventricles (hollow spaces) in the brain.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• The fluid that is contained within the brain ventricles, the subarachnoid space and the central canal of the spinal cord.
  NCI
  U.S. National Cancer Institute, 2021
• Transudate contained in the subarachnoid space.
  Digital Anatomist
  University of Washington, 2003
• Cerebrospinal fluid (CSF), clear, colourless liquid that fills and surrounds the brain and the spinal cord and provides a mechanical barrier against shock. Formed primarily in the ventricles of the brain, the cerebrospinal fluid supports the brain and provides lubrication between surrounding bones...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025