What is the primary function of the blood-brain barrier?

The primary function of the blood-brain barrier is to protect the brain from harmful substances. This specialized barrier consists of tightly packed endothelial cells that line the brain's blood vessels, preventing certain molecules and pathogens in the bloodstream from entering the brain tissue. By selectively allowing nutrients and essential molecules to pass while blocking potentially dangerous chemicals, toxins, and pathogens, the blood-brain barrier plays a crucial role in maintaining the brain's microenvironment. This protective mechanism is vital for preserving neural function and overall brain health, ensuring that the delicate balance necessary for proper brain activity is maintained.