In English | En español
Questions About Cancer? 1-800-4-CANCER

NCI Dictionary of Cancer Terms

Page Options

  • Print This Page

Widget



blood-brain barrier  listen  (blud-brayn BAYR-ee-er)

  A network of blood vessels and tissue that is made up of closely spaced cells and helps keep harmful substances from reaching the brain. The blood-brain barrier lets some substances, such as water, oxygen, carbon dioxide, and general anesthetics, pass into the brain. It also keeps out bacteria and other substances, such as many anticancer drugs. Also called BBB.