Very few people have heard about glial cells. They do not have the same “superstar” status as the nerve cells or neurons. However, glial cells are just as important as neurons in the function of the nervous system. In fact they outnumber the neurons by a ratio of about 10 (glial cells) to 1 (neuron), maybe even more in some parts of the brain.
So what are glial cells? Well, they are known as the supporting cells of the nervous system. They provide support to both the cell body and the cell processes of the nerve cells. However, they do much more than just provide support: they also provide nutrition, form myelin sheath, maintain homeostasis, insulate neurons, and modulate nerve impulse transmission. They also guide neurons in making the correct connections during development. Some glial cells even act as scavengers and clean-up crew because they destroy pathogens and remove dead neurons.
There are specialized glial cells for each of those functions. For example, there is a different glial cell that forms the myelin sheath. A different glial cell also provides nutrition and another acts as scavenger. So they come in different names like microglia, oligodendroglia, astroglia, ependyma, and Schwann cell.
Glia is actually Greek for “glue.” So glial cells kind of “glue” together the components of our nervous system.