Nonneuronal Cells of the Nervous System

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Nonneuronal Cells of the Nervous System

• Melissa Metzler

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Glial Cells

• Make up about 90 of the cells in the nervous
  system but only 50 of the volume.
• Cannot generate or transmit nerve signals.
• They are responsible for the physical and
  metabolic support of the neurons.

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Types of Nonneuronal Cells

• Four types associated with the central nervous
  system.
• Astrocytes, oligodendrocytes, microglia, and
  ependymal cells
• Two types associated with the peripheral nervous
  system
• Satellite cells and Schwann cells.

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Astocytes

• Star-shaped cell that provides glucose and
  removes ammonia from the neurons.
• Also regulates potassium and neurotransmitters
  around synapses.

http//fig.cox.miami.edu/cmallery/150/neuro/neuro
physiology.htm
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Astrocytes Continued

• Form a barrier around the blood vessels in the
  brain (blood-brain barrier).
• Keeps certain substances from moving into the
  brain.
• Helps to direct neurons during embryo development
  and supplies the neurons with growth factors.

www.rit.edu/umagwww/ winter2002/gallery.html
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Oligodendrocytes and Microglia

• Oligodendrocytes wrap extension of their cell
  membranes around sections of the axon (myelin
  sheaths).
• Myelin sheaths help to transmit nerve impulses.
• Microglia remove pathogens and cell debris from
  the brain.

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Ependymal Cells

• Lines the ventricles or hollow spaces of the
  central nervous system and secretes cerebrospinal
  fluid
• Cerebrospinal fluid acts as a shock absorber and
  helps to carry nutrients to the cells.

http//faculty.southwest.tn.edu/rburkett/AP1_nerv
ous_system_lab.htm
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Nonneuronal Cells of the Peripheral Nervous System

• Satellite cells protect the cells of the ganglia
• Schwann cells form a myelin sheath around a
  segment of an axon.

www.steve.gb.com/science/ nervous_system.html
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References

• Pasternak, Jack J. An Introduction to Human
  Molecular Genetics Mechanisms of Inherited
  Diseases. Second Edition. John Wiley Sons, Inc.
  2005.
• Widmaier, Eric P. Hershel, Raff Strang, Kevin
  T. Vanders Human Physiology The Mechanisms of
  Body Functions. Tenth Edition. Mcgraw-Hill. 2006.