blood-brain barrier

[ bluhd-breyn ]

noun

, Physiology.

1. a layer of tightly packed cells that make up the walls of brain capillaries and prevent substances in the blood from diffusing freely into the brain: passage across the cell membranes is determined by solubility in the lipid bilayer or recognition by a transport molecule.

blood-brain barrier

1. A physiological mechanism that alters the permeability of capillaries in the brain, so that some substances, such as certain drugs, are prevented from entering brain tissue, while other substances are allowed to enter freely.

blood-brain barrier

1. The separation of the brain , which is bathed in a clear cerebrospinal fluid, from the bloodstream. The cells near the capillary beds external to the brain selectively filter the molecules that are allowed to enter the brain, creating a more stable, nearly pathogen-free environment.

Notes

Oxygen , glucose , and white blood cells are molecules that are able to pass through this barrier. Red blood cells cannot.

Word History and Origins

Origin of blood-brain barrier¹

First recorded in 1940–45

Example Sentences

That’s why researchers are designing next-generation therapies with the intent that they will cross the blood-brain barrier, stay there and more effectively treat cancer that has spread to the brain.

From Ozy

“Drugs that can cross the blood-brain barrier have huge potential benefits for patients.”

From Ozy

Susan Rosenbaum, founder and CEO of Lauren Sciences, is using a patented nanovesicle technology that aims to deliver existing FDA-approved cancer drugs through the blood-brain barrier.

From Ozy

It’s too large and gets blocked by that thin film of cells, the blood-brain barrier.

From Singularity Hub 

It’s been used to blast open the blood-brain barrier, which protects the brain from toxins in the blood, in an effort to allow medical drugs to flow into the brain with occasional subsequent damage.

From Singularity Hub 

But how exactly did those fetal cells (or some of the DNA from them) cross the blood-brain barrier and enter the brain?

From The Daily Beast