362
UNIT THREE
Fluid-filled cavity
of the brain or
spinal cord
Ependymal
cell
Microglial cell
Myelin
sheath (cut)
Axon
Node of
Ranvier
Oligodendrocyte
Astrocyte
Capillary
Neuron
FIGURE 10.8
±Types±of±
neuroglia in the central
nervous system include the
astrocyte, oligodendrocyte,
microglial cell, and ependymal
cell. Cilia are on most
ependymal cells during
development and early
childhood, but in the adult are
mostly on ependymal cells in
the ventricles of the brain.
TABLE
10.1
|
Types of Neurons
A. ClassiF
ed by Structure
Type
Structural Characteristics
Location
1. Multipolar neuron
Cell body with many processes, one of which is an axon, the rest
dendrites
Most common type of neuron in the brain and spinal cord
2. Bipolar neuron
Cell body with a process, arising from each end, one axon and one
dendrite
In specialized parts of the eyes, nose, and ears
3. Unipolar neuron
Cell body with a single process that divides into two branches and
functions as an axon
Found in ganglia outside the brain or spinal cord
B. ClassiF
ed by ±unction
Type
±unctional Characteristics
Structural Characteristics
1. Sensory neuron
Conducts nerve impulses from receptors in peripheral body parts into
the brain or spinal cord
Most unipolar; some bipolar
2. Interneuron
Transmits nerve impulses between neurons in the brain and spinal cord
Multipolar
3. Motor neuron
Conducts nerve impulses from the brain or spinal cord out to
ectors—muscles or glands
Multipolar
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