3. • Classification of neuroglial cells.
• Function of neuroglial cells.
• Location of neuroglial cells.
Neuroglial cell:
•Although glia cells DO NOT carry nerve impulses (action
potentials) they do have many important functions. In fact,
without glia, the neurons would not work properly!
4. Structure of Neuroglia:
• Neuroglia,also called glial cells or simply glia,are non-neuronal
cells in the entral nervous system (brain and spinal cord) and
the peripheral nervous system.
• The term neuroglia drives from a Greek,and the orignal
impression wa,that they were the glue of the nervous system.
• Glial cells (nuroglia) are the non-excitable supporting cells of
the nervous system.All glial cells are much smaller but for
more numerous than the nerve cells.
• They form a major components of the nervous tissue .
• Neuroglia play a ey role in synapse formation and mainteance.
• They are ten times more abundant in human brain than
neurons.
5. Functions of Glial Cells:
• They provide mechanical support to neurons.
• Because of their non-conducting nature,the glial cells act as insulator
between the neuros and prevent neuronal impulses from spreading in
unwanted direction.
• They can remove the foreign material and cell debris by phagocytosis.
• They can repair the damaged areas of nervous tissue by proliferation
(gliosis) they form glial scar tisssue,and fill the gaps by degenerated
neurons.
• Glial cells can take up and store neurotransmitters released by the
neighbouring synapses.The can-either be metabolized or released gain
from the glial cells.
• They help in neuronal functions by maintaining a suitable metabolic and
ionic environment for the neurons.
• Oligodendrocytes myelinate tracts.
6. • According To Size:
• The neurolial cells, found in the parenchyma of brain
and spinal cord,are broadly classsified as:
• Macroglia,of ectodermal (neural) origin,comprising
astrocytes, oligodendrocytes, and glioblasts.
• Microglia, of mesodermal origin.
– Types of Neuroglia:
– Are various types-four in CNS &Two in PNS are discussed
– Neuroglia in the CNS:Thre are four types of neuroglia found
within the central nervous system.
7. • Astrocytes-maintain the blood brain barrier and
preserve the chemical environment by recycling
ions and neurotransmitter.
• Oligodendrocytes-myelinate axons in the central
nervous system and provide an overall structural
framework.
• Ependymal Cells-line ventricles (brain) and central
canal (spinal cord) and are involved in the
production of cerebrospinal fluid.
• Microglia-remove cell debris,wastes and pathogens
via phagocytosis.
10. These from
the main suppporting tissue of
the CNS.
They are found in large near
blood vessels.
Their function is same like
fibrolast of connective tissues.
They are regulators of blood
brain barrier.
They reserve brain glycogen
energy.
11. • Smaller than Astrocytes.
• They form myelin sheath.
• They found in clusters,have
round cell bodies.
• Found near and along the lenght
of myelinated nerve fibers.
• They form and maintain nerve
fiber around axons in CNS.
12. They are found along the
pervascular coat of blood
vessels in CNS.
They enlarge and become
phagocytic in the area of
inflamation.
These are small cells,flat cell
body with short cellular
processes.
13. • These cells form the epithilial
lining of the ventricles of the
brain.
• And central of the spinal cord.
• These cells form choroid
plexuses of the ventricles
secrete CSF,
14. • These form myelin sheath to
peripheral nerves.
• Glial cells that myelinate the
axons of peripheral
nerve.These cells wrap their
cytoplasm in a spiral fashion
around short segments of
axons.Because the myelin
sheath is formed from
numerous Schwann cells
arranged sequentially along the
axons.
