blood-brain barrier

noun

ˈbləd-ˈbrān- 

: a naturally occurring barrier created by the modification of brain capillaries (as by reduction in fenestration and formation of tight cell-to-cell contacts) that prevents many substances from leaving the blood and crossing the capillary walls into the brain tissues

Examples of blood-brain barrier in a Sentence

Recent Examples on the Web

Neuroinflammation, brain shrinkage, disruption of the blood-brain barrier and more have been documented in adults, as have cognitive deficits. —Blake Murdoch, Scientific American, 18 Oct. 2024

Once the edible is ingested, the THC is metabolized by the liver and transformed into 11-hydroxy-THC, a compound that’s four times faster in crossing the blood-brain barrier than THC. —Tribune Content Agency, The Mercury News, 4 Oct. 2024

The particles were also able to cross the blood-brain barrier. —Kaitlin Sullivan, NBC News, 16 Sep. 2024

Due to their smaller size and shape, Amato-Lourenço added, particles are more likely than fibers to bypass microglia cells in the blood-brain barrier, a membrane that protects the brain and spinal cord from many harmful substances. —Sandee Lamotte, CNN, 16 Sep. 2024

Word History

First Known Use

1934, in the meaning defined above

Medical Definition

blood-brain barrier

noun

: a naturally occurring barrier created by the modification of brain capillaries (as by reduction in fenestration and formation of tight cell-to-cell contacts) that prevents many substances from leaving the blood and crossing the capillary walls into the brain tissues

—abbreviation BBB