Blood-brain barrier (BBB)

The blood-brain barrier (BBB) is a protective system of the brain's blood vessels that tightly controls what substances can pass from the bloodstream into the brain tissue. It works like a selective filter, allowing essential nutrients like oxygen and glucose to enter while blocking harmful substances such as toxins and certain pathogens. This barrier is made up of specialized cells that tightly seal the blood vessels, maintaining a stable environment for the brain to function properly. The BBB is crucial for protecting brain health, but it also poses challenges for delivering medications to treat brain disorders.