DOMESTIC EXERCISE



VIII.

DOMESTIC EXERCISE.


In a work which aims to influence women to train the young to honor
domestic labor and to seek healthful exercise in home pursuits, there
is special reason for explaining the construction of the muscles and
their connection with the nerves, these being the chief organs of
motion.

The muscles, as seen by the naked eye, consist of very fine fibres or
strings, bound up in smooth, silky casings of thin membrane. But each
of these visible fibres or strings the microscope shows to be made up
of still finer strings, numbering from five to eight hundred in each
fibre. And each of these microscopic fibres is a series or chain of
elastic cells, which are so minute that one hundred thousand would
scarcely cover a capital O on this page.

[Illustration: Fig. 51.]
[Illustration: Fig. 52.]

The peculiar property of the cells which compose the muscles is their
elasticity, no other cells of the body having this property. At Fig.
51 is a diagram representing a microscopic muscular fibre, in which
the cells are relaxed, as in the natural state of rest. But when the
muscle contracts, each of its numberless cells in all its small fibres
becomes widened, making each fibre of the muscle shorter and thicker,
as at Fig. 52. This explains the cause of the swelling out of muscles
when they act.

Every motion in every part of the body has a special muscle to produce
it, and many have other muscles to restore the part moved to its natural
state. The muscles that move or bend any part are called _flexors_,
and those that restore the natural position are called _extensors_.

[Illustration: Fig. 53]

Fig. 53 represents the muscles of the arm after the skin and flesh are
removed. They are all in smooth silky cases, laid over each other, and
separated both by the smooth membranes that encase them and by layers
of fat, so as to move easily without interfering with each other. They
are fastened to the bones by strong tendons and cartilages; and around
the wrist, in the drawing, is shown a band of cartilage to confine
them in place. The muscle marked 8 is the extensor that straightens
the fingers after they have been closed by a flexor the other side of
the arm. In like manner, each motion of the arm and fingers has one
muscle to produce it and another to restore to the natural position.

The muscles are dependent on the brain and nerves for power to move.
It has been shown that the gray matter of the brain and spinal marrow
furnishes the stimulating power that moves the muscles, and causes
sensations of touch on the skin, and the other sensations of the several
senses. The white part of the brain and spinal marrow consists solely
of conducting tubes to transmit this influence. Each of the minute
fibrils of the muscles has a small conducting nerve connecting it with
the brain or spinal marrow, and in this respect each muscular fibril
is separate from every other.

When, therefore, the mind wills to move a flexor muscle of the arm,
the gray matter sends out the stimulus through the nerves to the cells
of each individual fibre of that muscle, and they contract. When this
is done, the nerve of sensation reports it to the brain and mind. If
the mind desires to return the arm to its former position, then follows
the willing, and consequent stimulus sent through the nerves to the
corresponding muscle; its cells contract, and the limb is restored.

When the motion is a compound one, involving the action of several
muscles at the same time, a multitude of impressions are sent back and
forth to and from the brain through the nerves. But the person acting
thus is unconscious of all this delicate and wonderful mechanism. He
wills the movement, and instantly the requisite nervous power is sent
to the required cells and fibres, and they perform the motions required.
Many of the muscles are moved by the sympathetic system, over which
the mind has but little control.

Among the muscles and nerves so intimately connected, run the minute
capillaries of the blood, which furnish nourishment to all.

[Illustration: Fig. 54]

Fig. 54 represents an artery a _a_, which brings pure blood to a muscle
from the heart. After meandering through the capillaries at _c_, to
distribute oxygen and food from the stomach, the blood enters the vein,
_b_, loaded with carbonic acid and water taken up in the capillaries, to
be carried to the lungs or skin, and thrown out into the air.

The manner in which the exercise of the muscles quickens the circulation
of the blood will now be explained. The veins abound in every part of
every muscle, and the large veins have _valves_ which prevent the
blood from flowing backward. If the wrist is grasped tightly, the veins
of the hand are immediately swollen. This is owing to the fact that
the blood is prevented from flowing toward the heart by this pressure,
and by the vein-valves from returning into the arteries; while the
arteries themselves, being placed deeper down, are not so compressed,
and continue to send the blood into the hand, and thus it accumulates.
As soon as this pressure is removed, the blood springs onward from the
restraint with accelerated motion. This same process takes place when
any of the muscles are exercised. The contraction of any muscle presses
some of the veins, so that the blood can not flow the natural way,
while the valves in the veins prevent its flowing backward. Meantime
the arteries continue to press the blood along until the veins become
swollen. Then, as soon as the muscle ceases its contraction, the blood
flows faster from the previous accumulation.

If, then, we use a number of muscles, and use them strongly and quickly,
there are so many veins affected in this way as to quicken the whole
circulation. The heart receives blood faster, and sends it to the lungs
faster. Then the lungs work quicker, to furnish the oxygen required
by the greater amount of blood. The blood returns with greater speed
to the heart, and the heart sends it out with quicker action through
the arteries to the capillaries. In the capillaries, too, the decayed
matter is carried off faster, and then the stomach calls for more food
to furnish new and pure blood. Thus it is that exercise gives new life
and nourishment to every part of the body.

It is the universal law of the human frame that _exercise_ is
indispensable to the health of the several parts. Thus, if a
blood-vessel be tied up, so as not to be used, it shrinks, and becomes
a useless string; if a muscle be condemned to inaction, it shrinks in
size and diminishes in power; and thus it is also with the bones.
Inactivity produces softness, debility, and unfitness for the functions
they are designed to perform.

Now, the nerves, like all other parts of the body, gain and lose
strength according as they are exercised. If they have too much or too
little exercise, they lose strength; if they are exercised to a proper
degree, they gain strength. When the mind is continuously excited, by
business, study, or the imagination, the nerves of emotion and sensation
are kept in constant action, while the nerves of motion are unemployed.
If this is continued for a long time, the nerves of sensation lose
their strength from over-action, and the nerves of motion lose their
power from inactivity. In consequence, there is a morbid excitability
of the nervous, and a debility of the muscular system, which make all
exertion irksome and wearisome.

The only mode of preserving the health of these systems is to keep up
in them an equilibrium of action. For this purpose, occupations must
be sought which exercise the muscles and interest the mind; and thus
the equal action of both kinds of nerves is secured. This shows why
exercise is so much more healthful and invigorating when the mind is
interested, than when it is not. As an illustration, let a person go
shopping with a friend, and have nothing to do but look on. How soon
do the continuous walking and standing weary! But, suppose one, thus
wearied, hears of the arrival of a very dear friend: she can instantly
walk off a mile or two to meet her, without the least feeling of
fatigue. By this is shown the importance of furnishing, for young
persons, exercise in which they will take an interest. Long and formal
walks, merely for exercise, though they do some good, in securing fresh
air, and some exercise of the muscles, would be of triple benefit if
changed to amusing sports, or to the cultivation of fruits and flowers,
in which it is impossible to engage without acquiring a great interest.

It shows, also, why it is far better to trust to useful domestic
exercise at home than to send a young person out to walk for the mere
purpose of exercise. Young girls can seldom be made to realize the
value of health, and the need of exercise to secure it, so as to feel
much interest in walking abroad, when they have no other object. But,
if they are brought up to minister to the comfort and enjoyment of
themselves and others, by performing domestic duties, they will
constantly be interested and cheered in their exercise by the feeling
of usefulness and the consciousness of having performed their duty.

There are few young persons, it is hoped, who are brought up with such
miserable habits of selfishness and indolence that they can not be
made to feel happier by the consciousness of being usefully employed.
And those who have never been accustomed to think or care for any one
but themselves, and who seem to feel little pleasure in making
themselves useful, by wise and proper influences can often be gradually
awakened to the new pleasure of benevolent exertion to promote the
comfort and enjoyment of others. And the more this sacred and elevating
kind of enjoyment is tasted, the greater is the relish induced. Other
enjoyments often cloy; but the heavenly pleasure secured by virtuous
industry and benevolence, while it satisfies at the time, awakens fresh
desires for the continuance of so ennobling a good.