11-1
11-2
11-3
11-4
At the end of this Lecture you should know
• Structural & functional unit of CNS
• Glial Cells & their functions
11-5
Cells of Nervous System
1.Neurons; Structural & Functional Unit of
Nervous System
– Receive stimuli and transmit in the form of
action potentials
2. Neuroglia or glial cells
– Support and protect neurons
11-6
Types of Neurons
11-7
11-8
Neuroglia of CNS
• Astrocytes
• Ependymal cells
• Microglia
• Oligodendrocytes
11-9
Neuroglia of PNS
• Schwann cells
• Stellate cells
11-10
Astrocytes
11-11
Functions of Astrocytes
• They hold the neurons together in proper spatial
relationships.
• Act as a scaffold to guide neurons to their proper
final destination during fetal brain development.
• Regulate extracellular fluid composition in the brain
especially K+
• Promote tight junctions to form blood-brain barrier
(BBB)
11-12
Functions of Astrocytes
•
•
•
•
•
•
Glycogen storage and lactate
Vasomodulation
Regulate transmission of AP
Provide repairing
Promote mylination activity by Oligodendrocytes
Long term potentiation in Hippocampus
11-13
Ependymal Cells
• Line brain ventricles and spinal cord central
canal.
Help to form choroid plexuses that secrete
CSF
11-14
Microglia
• Specialized macrophages
• Monitor synaptic connections
(Circuitry, Plasticity)
11-15
Oligodendrocytes
Form myelin sheaths of surrounding axons
Upto 50 axons can by mylinated
11-16
Recent Advances in Glial Cell Research
• Boosting glial function could protect the
brain
• Correcting glial dysfunction may prevent
neurodegenerative disorders
Alzheimer
Parkinsons
11-17
11-18
Neuroglia of Peripheral
Nervous System
• Schwann cells or
neurolemmocytes
– Wrap around portion of
only one axon to form
myelin sheath
• Stellate cells
– Surround neuron cell
bodies in dorsal root
ganglia,
– provide support and
nutrients
11-19
11-20