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

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

Some forms of magnesium may not readily cross the blood-brain barrier. —Allison Herries, Verywell Health, 10 Sep. 2024

In Drosophila, the presence of dietary amino acids is sensed by the fat body, a functional equivalent of the human liver and adipose tissue, which triggers the production of insulin-like peptides by cells in the blood-brain barrier. —New Atlas, 15 Aug. 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