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

However, the team found endocannabinoid receptors in and around the blood-brain barrier. —William A. Haseltine, Forbes, 25 Mar. 2025

But our brains are designed to keep things out, through something called the blood-brain barrier. —Megha Satyanarayana, Scientific American, 14 Feb. 2025

Creatine crosses the blood-brain barrier, and neurons can make it within the central nervous system.11 Brain creatine levels may decrease during stressful conditions. —Melissa Nieves, Verywell Health, 13 Mar. 2025

This occurs when cancer cells migrate through the blood-brain barrier. —Charna Flam, People.com, 7 Mar. 2025

Word History

First Known Use

1934, in the meaning defined above

Rhymes for blood-brain barrier

• noncarrier
• carrier

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