Editing Cerebrospinal fluid (section)

===Anesthesia and chemotherapy===
{{See also|Blood–cerebrospinal fluid barrier}}
Some [[anesthetic]]s and [[chemotherapy]] drugs are injected [[intrathecal]]ly into the subarachnoid space, where they spread around CSF, meaning substances that cannot cross the [[blood–brain barrier]] can still be active throughout the central nervous system.<ref name=HOCKING2004/><ref>{{cite web|title=Intrathecal Chemotherapy for Cancer Treatment {{!}} CTCA|url=http://www.cancercenter.com/treatments/intrathecal-chemotherapy/|website=CancerCenter.com|access-date=22 May 2017|archive-date=1 January 2018|archive-url=https://web.archive.org/web/20180101135319/https://www.cancercenter.com/treatments/intrathecal-chemotherapy/|url-status=dead}}</ref>  [[Baricity]] refers to the density of a substance compared to the density of human cerebrospinal fluid and is used in [[regional anesthesia]] to determine the manner in which a particular drug will spread in the [[intrathecal]] space.<ref name="HOCKING2004">{{cite journal | vauthors = Hocking G, Wildsmith JA | title = Intrathecal drug spread | journal = British Journal of Anaesthesia | volume = 93 | issue = 4 | pages = 568–78 | date = October 2004 | pmid = 15220175 | doi = 10.1093/bja/aeh204 | doi-access = free }}</ref>