^ Supporting cells of the CNS (neuroglial cells); outnumber neurons 10:1
♦ Stellate morphology
■ Fibrous astrocytes in white matter
■ Protoplasmic astrocytes in gray matter
figure 8.2. The reflex arc.
Spinal cord Ventral root figure 8.2. The reflex arc.
■ Physical support
■ Transport nutrients
■ Maintain ionic homeostasis
■ Take up neurotransmitters
■ Form glial scars (gliosis)
♦ Present in white and gray matter
♦ Interfascicular oligodendrocytes are located in the white matter of the CNS, where they produce the myelin sheath.
• Ependymal cells. Line ventricles
♦ Not a true neuroglial cell; derived from mesoderm whereas neu-roglial cells, as well as neurons, are derived from ectoderm
♦ Highly phagocytic cells
^ Supporting cells of the PNS. Schwann cells
• Satellite Schwann cells surround cell bodies in ganglia
• Ensheathing Schwann cells
♦ Surround unmyelinated axons. Numerous axons indent the Schwann cell cytoplasm and are ensheathed only by a single wrapping of plasma membrane.
♦ Produce the myelin sheath around axons
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