What is blood barrier?
What is blood barrier?
(blud-brayn BAYR-ee-er) A network of blood vessels and tissue that is made up of closely spaced cells and helps keep harmful substances from reaching the brain. The blood-brain barrier lets some substances, such as water, oxygen, carbon dioxide, and general anesthetics, pass into the brain.
What forms the blood barrier?
The blood-brain barrier is a multicellular, compound structure composed of endothelial cells, pericytes and astrocytes in direct contact with brain tissue. The BBB is a compound structure following the brain’s labyrinth of vasculature. It’s composed of 4 cell types: Endothelial Cells.
What are the functions of BBB?
The purpose of the blood–brain barrier is to protect against circulating toxins or pathogens that could cause brain infections, while at the same time allowing vital nutrients to reach the brain.
What is the blood-brain barrier called?
The blood–brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that prevents solutes in the circulating blood from non-selectively crossing into the extracellular fluid of the central nervous system where neurons reside.
What can cross the BBB?
Only water, certain gases (e.g. oxygen), and lipid-soluble substances can easily diffuse across the barrier (other necessary substances like glucose can be actively transported across the blood-brain barrier with some effort).
Is the blood-brain barrier a membrane?
The blood-brain barrier is the barrier between the cerebral capillary blood and the interstitial fluid of the brain. It is made up of capillary endothelial cells and basement membrane, neuroglial membrane, and glial podocytes, i.e., projections of astrocytes.
How is blood-brain barrier formed?
A layer of brain endothelial cells connected by tight junctions forms the blood-brain barrier. The intimate contact of these specialized endothelial cells with different cell types constitutes the NVU. A basement membrane embeds the brain endothelial cells, the pericytes, and astrocytes.
What does the blood-brain barrier allow to pass?
Small polar molecules, such as glucose, amino acids, organic anions and cations, and nucleosides, can cross the blood-brain barrier by carrier-mediated transport.