The labor world. [volume] (Duluth, Minn.) 1896-current, 1907-08-03
HEALTH AND HARMONY
BY RATIONAL METHODS
Human Physiology as Taught and
Inculated in the Chiro-
practic School.
Fully Explained by Leading Men,
Der Of the Profession in
Duluth.

0u4uVls
Contribution No. 2 Of the Series.
THE NERVOUS SYSTEM.
The nervous system may be defined
| as a wonderfully constructed appara-
tus. designed to unite and coordinate
the powers and functions of every
organ and tissue of the body, and
thus enable the individual to MAIN
| tain healthful and harmonious re-
lationship to the external world.
Its Main Divisions.
This marvellous instrumentality is
a two-fold combination. One is known
as the cerebro-splnal system, and
| consists Of Cd the brain and spinal
cord: and CD the cranial and spinal
| nerves. The other is known as the
sympathetic system, and consists Of
CD a chain Of ganglia connected by
longitudinal nerve filaments. extend
ing on each side of the spinal column,
from the base Of the skull to the
most rudimentary part Of the verte-
bral column, a bone called the coc-
cyx and (2) the collection OF gan
glia situated in the head, face, thor
ak, abdomen and pelvis, and to which
are united system Of inter-com-
municating nerves, many Of which
are connected with the cerebro-spinal>
system.
Officers and Functions.
The whole is a very complex ar
rangement, and TO be methodical I
shall discuss each system separately;
but, as possibly contributing to an
easier understanding of so elaborate
subject, let me say in general way,
that the cerebro- spinal system is that
which controls or produces all the
motions and activities Of the body and
limbs that are subject to the will and
commonly called voluntary action, and
the sympathetic system is the motive
power which gives enuergy, direction
and activity to those bodily organs
| and functions that work independent
! Of our will, and commonly known as
! involuntary action. There are stages
| in which the line Of demarkation be-
| tween the two functions is not very
easy to locate, by reason of intercom-
municating nerves, but the distinction
| is germane nevertheless.
| The Spinal Nerves.
Referring to the cerebo spinal sys-
tenn, and more particularly to the
| spinal nerves, these are thirty-one in
| number on each side Of the spinal
cord. Each nerve energies from the
cord by two roots, called, respectively
| the ventral and the dorsal roots. The
ventral roots are also called anterior
and the dorsal roots posterior, names
determined by the aspect Of the cord
from which they arise.
Near their emergence from the cord
the dorsal or posterior roots presents
an enlargement called a ganglion.
This is knot or bundle Of nerve fib-
ers embedded in a. capsule Of con-
nective tissue. Beyond this ganglion
the two roots unite, and become
bound together to form a main trunk,
which with it's innumerable tribu-
tary branches connects the brain and
| spinal cord with. all the remaining
structures of the body
| Functional Classification.
A nerve is really bundl~ or aggre-
cation of an infinite number Of fibers,
each Of which is histologically dis
tinct and Independent. The class Of
nerves that carry messages or trans
init enrvous energy from the brain
or spinal cord to all parts Of the body
are called efferent, motor, or centri-
fugal nerves.; and those which serve
for the transmission of messages to
the brain and spinal cord and give
rise to sensations are called afferent,
sensory or centrpital nerves.
1t has been ascertained by I'M
doubted experiments that the ventral
or anterior root Of nerve contains
all the efferent or motor f;bers, and
that the dorsal or posterior root con-
tafns all the afferent or sensory fibers,
and that these fibers do not loose
their characteristic functions by the
main trunk.
Source Of Energy.
The spinal cord is but continual
ton or extension of the substance Of
the brain, and the motor fibers which
conduct volitional impulses from the
brain arise in the motor centers Of
the cerebrum. BY a process Of the
motor tract called "decussation," and
too intricate for discussion here, each
half Of the brain governs the muscu-
lar movement Of the opposite side Of
the body, and through a similar pro-
cess in the sensory tract, each half
of the brain governs the sensibility of
the opposite side Of the body.
Distribution Of Nerves.
The motor nerves or those Of VOL
untary motion are distributed mainly
to the muscles and enable us to gov
ern them at will. We move our
hands, feet head and body in accord
ance with the determinations of the
Will. The sensor or Involuntary ner-
YES are mostly upon the surface of
the body, SITUATED as sentinels upon
the outer walls to warn against tho
approach Of all enemies to life and
health" So minute are their rami-
fications that the point Of the finest
needle thrust through any part of the