128).
*End-to-end Connections.*--These consist of loose end-to-end unions of the
fiber branches of certain neurons with the dendrites of other neurons. The
purpose of such connections is to provide the means of communication
between different parts of the body. There appears to be no actual uniting
of the fiber branches with the dendrites, but they come into relations
sufficiently close to establish _conduction pathways_, and these extend
throughout the body (Fig. 129). They connect all parts of the body with
the brain and spinal cord, while connections within the brain and cord
bring the parts into communication with each other.
[Fig. 129]
Fig. 129--*Diagram of a nerve path* starting at the skin, extending through
the spinal cord, and passing out to muscles. A division of this path also
reaches the brain.
*Nature of the Nervous System.*--The nervous system represents the sum
total of the neurons in the body. In some respects it may be compared to
the modern telephone system. The neurons, like the electric wires, connect
different places with a central station (the brain and spinal cord), and
through the central station connections are established between the
different places in the system.
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