Type O negative blood (red cells) can be transfused to patients of all blood types. It is always in great demand and often in short supply. Type AB positive plasma can be transfused to patients of all other blood types. AB plasma is also usually in short supply.
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.
Blood-Brain Barrier. formed by endothelial cells; joined by tight junctions; protects neurons from toxic substances, allows the exchange of nutrients and waste products between neurons and blood, prevents fluctuations in composition of blood from affecting the functions of the brain; influenced by astrocytes.