January 15, 2014
Cells of NS. Anatomy of a neuron
-conduction – myelinated neurons can conduct much faster than unmyelinated neurons
Many shapes and sizes
Endoplasmic reticulum help produce fats while ribosomes help in the production of proteins
The golgi complex helps package “things” i.e. neurotransmitters into vesicles
Any given neuron produces two ypes of neurotransmitters small neurotransmitters like
dopamine and serotonin as well as larger neurotransmitters
Cell membrane is a lipid bilayer with both signal proteins and channel proteins embedded within
Channel proteins are the same as ion channels. Ion channels are usually very specific and will
only let one specific ion through the channel. Signal protein is a metabotropic protein that can
have many different effects on a cell and not simply the opening of a channel.
For every one neuron you have about 10 glial cells depending on what area you are looking at.
In areas of high myelination you have many more glial cells (because glial cells produce myelin
and support other cells in both structure and nutrition of other cells)
Four classes of Glial cells
-oligodenrocytes – extensions rich in myelin, create myelin sheaths In CNS and only in
the CNS. Can produce more than one sheath, do not exist in the PNS.
-Schwann cells - each Schwann cell produces a single sheath in the PNS, can guide
axonal regeneration. Missing the protein component that is in the oligodendrcytes.
-Astrocytes – largest glia, star shaped, many functions. This is the cell that is supposed
to be able to communicate with neurons
-microglia – involved in response to injury or disease, cleaning up the debris
Myelin providing glia Oligodendrocytes Schwann cells
Clusters of cell bodies Nuclei (singular nucleus) Ganglia (singular ganglion)
Bundles of axons Tracts Nerves
Directions in the Vertebrate NS -Superior/ Inferior – one stru