Related Experiment Video
Updated: Jul 21, 2026

A Human Blood-Brain Interface Model to Study Barrier Crossings by Pathogens or Medicines and Their Interactions with the Brain
Published on: April 9, 2019
The blood-brain barrier: morphology, molecules, and neurothelin
1Naturwissenschaftliches und Medizinisches Institut Universität Tübingen, Reutlingen, Germany.
Abstract:
The blood-brain barrier (BBB) is a complex structure formed by vascular endothelial cells, which serve to stabilize the homeostasic processes that are essential for neural functioning. The barrier relies on tight junctions between neighboring endothelial cells and a highly restricted passage of blood-borne components through the endothelial lining. Selective transport mechanisms guarantee the essential import and export of metabolites through the BBB into and out of the neural microenvironment. The dual functions of barrier and carrier depend on distinct proteins, some of which have been characterized in detail.
Related Concept Videos
The Blood-brain Barrier
Physiological Barriers
The blood endothelial barrier is the most porous of these. It allows all small ionized, un-ionized, and lipophilic molecules to pass through the endothelial lining into the interstitial space...
Factors Affecting Drug Distribution: Physiological Barriers
The capillary endothelial barrier allows only smaller molecules below 600 Da (Daltons) to pass through. It also restricts drugs like heparin that are bound to blood components, limiting their movement within the bloodstream.
The...

