Understanding Psychology (10th Ed)

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M O D U L E 7
Neurons: The Basic 
Elements of Behavior
neurons
Nerve cells, the basic 
elements of the nervous system.
dendrite
A cluster of fi bers at one end 
of a neuron that receives messages 
from other neurons.
axon
The part of the neuron that 
carries messages destined for other 
neurons.
terminal buttons
Small bulges at the 
end of axons that send messages to 
other neurons.
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62 Chapter 
3 
Neuroscience and Behavior
Move
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Dendrites 
Cell body 
Axon (inside myelin sheath) 
Myelin sheath 
Terminal buttons 
FIGURE 1
The primary components of the specialized cell called the neuron, the basic element 
of the nervous system. A neuron, like most types of cells in the body, has a cell body, but it also 
contains structures that carry messages: the dendrites, which receive messages from other 
neurons, and the axon, which carries messages to other neurons or body cells. In this neuron, 
as in most neurons, the axon is protected by the sausage-like myelin sheath. What advantages 
does the treelike structure of the neuron provide?
follow a route that begins with the dendrites, continues into the cell body, and leads 
ultimately along the tubelike extension, the axon, to adjacent neurons. 
To prevent messages from short-circuiting one another, axons must be insulated 
in some fashion (just as electrical wires must be insulated). Most axons are insulated 
by a