There are approximately ten times as many glial cells in the nervous system as there are neurons. Collectively, the different types of glial cells perform very important functions in the nervous system. Test your basic knowledge of glial cells by taking this simple quiz.
(1) Myelinated axons allow the action potential to "jump" from node to node. This type of action potential propagation is known as __________ conduction.
(2) Along myelinated axons of the peripheral nervous system, each Schwann cell spans approximately __________, and the bare regions of the axon (nodes) in-between adjacent Schwann cells are approximately __________.
(3) Along myelinated axons of the peripheral nervous system, Schwann cells are responsible for forming a myelin sheath around the axon membrane. The gaps between adjacent Schwann cells, where the axon membrane is bare and readily exposed to the extracellualr fluid are referred to as the nodes of __________.
(4) In the mammalian nervous system, the ratio of the total number of glial cells to the total number of neurons is about: