PSYC 211 Lecture Notes - Lecture 5: Area Postrema, Frontal Lobe, White Matter
Document Summary
They are found all over the brain and spinal cord. Glia are found all around neurons and even physically encapsulate some parts of them. They help traffic nutrients and maintain molecular (ionic) stability in the extracellular space. They support many functions of the nervous system. It is estimated that glia cells outnumber neurons in the brain somewhere between 2:1 and 5:1. Support cells are divided into 3 categories: astrocyte is a glial cell that provides physical support and cleans up debris in the brain through phagocytosis. They control the chemical composition of the surrounding environment and help nourish neurons. Phagocytosis: glial cell engulfs garbage and breaks it down into component parts. These cells provide a supporting role, but this cell is not doing the job of information processes in the brain: oligodendrocytes support axons of neurons and produce the myelin sheath, which encapsulates axons. The sheath is not continuous; it is a series of segments.