Blood-brain barrier

Specialized non-fenestrated tightly-joined endothelial cells (tight junctions) that form a transport barrier for certain substances between the cerebral capillaries and the brain tissue.

A “wall” made up of a semipermeable layer of cells between the bloodstream and neurons that blocks out some substances and lets other materials through; helps to maintain a constant and stable environment for the brain.

The protective barrier (boundary) surrounding the central nervous system (CNS) (brain and spinal cord) that excludes many molecules and substances from freely diffusing or being transported into the brain tissues from the bloodstream.

The barrier that excludes many molecules and substances from freely diffusing or being transported into the brain tissues from the blood stream; acts as a protective function.

The specialized layer of endothelial cells that line all blood vessels in the brain. The BBB prevents most organisms (e.g., bacteria) and toxins from entering the brain via the bloodstream. However, the BBB does allow oxygen and needed nutrients (e.g., iron tryptophan, etc.) to enter the brain from the bloodstream. For example, receptors that line BBB cell surfaces (on the bloodstream side of the BBB) “latch onto” transferrin molecules (which contain iron molecules) as those transferrin molecules pass by in the bloodstream. These TRANSFERRIN RECEPTORS first bind to the (passing) transferrin molecules, transport those transferrin molecules through the BBB via a process called vaginosis, then release those transferrin molecules (in order to supply needed iron to the brain cells). Factors such as aging, trauma, stroke, multiple sclerosis, and some infections will cause an increase in the permeability of the BBB.

Blood vessels of the brain are covered with especially tight endothelial tissues, so that only few substances can enter the brain.

A barrier produced by the cells in the walls of the capillaries in the brain. This barrier permits passage of only certain substances.

The process by which some substances, which in other parts of the body will diffuse from capillaries, are held back by the endothelium of cerebral capillaries, preventing them from coming into contact with the fluids round the brain.

A barrier that selectively allows the passage of materials from the blood to the brain, Its purpose is to protect the brain from toxins.

The specialized anatomic arrangement of cerebral capillary walls which serves to restrict the passage of some drugs into the brain.

Barrier that exists between circulating blood and brain tissue, due presumably to a property of the blood vessels or covering tissues of the brain, whereby large molecules in the blood (e.g., a virus) are prevented from entering the brain and its surrounding fluid. The barrier serves to protect the central nervous system.

Selective mechanism that prevents passage of toxic or large chemicals into the brain while permitting essential substances such as oxygen and glucose to enter.

A double layer of cells that inhibits substances from crossing from the bloodstream into the fluid that bathes the brain tissues. It protects the brain by slowing or stopping the passage of certain chemical compounds (including some drugs) and disease-causing organisms (such as viruses) from the bloodstream into the brain.

Special characteristics of the capillary walls of the brain that prevent potentially harmful substances (including many medications) from moving out of the bloodstream into the brain or cerebrospinal fluid. It consists of either the perivascular glial membrane or the vascular endothelium or both.

A semipermeable cell layer around blood vessels in the brain and spinal cord that prevents large molecules, immune cells, and potentially damaging substances and disease-causing organisms (e.g., viruses) from passing out of the blood stream into the central nervous system (brain, optic nerves, and spinal cord). A break in the blood-brain barrier may underlie the disease process in MS.