Blood-brain barrier

blood-brain barrier

n. Abbr. BBB

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

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Blood-brain barrier

A blockade of cells separating the circulating blood from elements of the central nervous system (CNS); it acts as a filter, preventing many substances from entering the central nervous system.

Mentioned in: Lyme Disease

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blood-brain barrier,

n barrier formed by epithelial cells in the capillaries that supply the brain and central nervous system. This barrier selectively allows entry of substances such as glucose, some ions, and oxygen, while blocking entry of other substances. Also called
BBB.

Blood-brain barrier.

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blood-brain barrier,

n an anatomic-physiologic feature of the brain thought to consist of walls of capillaries in the central nervous system and surrounding glial membranes. It prevents or slows the passage of some drugs, other chemical compounds, radioactive ions, and disease-causing organisms such as viruses from the blood into the nerve tissues of the central nervous system.