FORMULA FOR THE LESSON ON THE MUSCLES.
1. Muscles are the red, elastic bands and bundles of thread like substance,
called flesh, which cover the bones and make the eyeballs, the eyelids, the
tongue, the heart, the lungs, and various other parts of the body.
2. There are about four hundred and fifty muscles in my body.
3. The work of the muscles is to support and move my bones, and different
parts of the body.
4. The muscles may be named the muscles of my head, the muscles of my
trunk, the muscles of my limbs.
5. The muscles of my head cover and move the parts of my head and face. The
muscles of my trunk cover and move the parts of my neck and trunk. The
muscles of my limbs cover and mote the parts of my arms and legs.
6. Those muscles are the weakest which I use least; those muscles are the
strongest which I exercise most in work or play.
7. If I would be strong and healthy,
my muscles must be used,
my muscles must be rested,
my muscles must be supplied with good blood.
I must exercise in work and play to make them strong; I must sleep, or
change my kind of work or play, to give them rest, when they are tired; I
must breathe pure air, take wholesome food and drink, and live in the
sunlight, to supply them with good blood; I must not weaken them by using
alcohol or tobacco.
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QUESTIONS FOR THE FORMULA.
1. Tell about the muscles.
2. How many muscles have you in your body?
3. Of what use are the muscles?
4. How may the muscles be named?
5. Tell about the muscles of the head, trunk, and limbs.
6. Which muscles are the weakest, and which are the strongest?
7. What is necessary if you would have strong and healthy muscles?
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CLASSES AND WORK OF THE MUSCLES.
The muscles are divided into two great classes: those which we may move as
we choose, called _voluntary_ muscles, and those over which we have no
power, called _involuntary_ muscles.
Some muscles support and move the various parts of the body, others have
different work to do. The heart, the great involuntary muscle, acts like an
engine to drive the blood throughout the body; the lungs draw in and throw
out the air in breathing; the stomach helps to churn and change food into
blood; the tongue is used in speaking and eating.
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QUESTIONS ON THE MUSCLES.
What are the muscles?--"The lean flesh of the body; bands and bundles of
fleshy threads which cover the body."
Of what use are the muscles to the body?--"They cover the bones; they
support and move the bones and different parts of the body."
Name some parts of the body which are made of muscles.--"The eyeballs, the
eyelids, the tongue, the heart, the lungs."
What color are the muscles?--"Red."
How do the muscles move the bones?--"By shortening or lengthening
themselves according to the way the bones are to be moved."
Tell how the muscles move your arm at the elbow.--"The muscles in the front
part of the arm shorten themselves, to draw my fore-arm toward the
shoulder; when I wish to stretch out the fore-arm these muscles lengthen,
while another set of muscles shorten, to draw the fore-arm away from the
upper arm."
What do you say about the muscles because they have the power to shorten
and lengthen themselves?--"They are elastic."
About how many muscles are there in your whole body?--"About four hundred
and fifty."
How may these be divided as you study about them?--"They may be divided
into the muscles of my head, the muscles of my trunk, and the muscles of my
limbs."
Of what use are the muscles of your head?--"They cover and move the parts
of my head and face."
Of what use are the muscles of your trunk?--"They move the parts of my neck
and trunk."
Of what use are the muscles of your limbs?--"They move the parts of my arms
and legs."
How can you make your muscles strong?--"By using them."
How can you make your muscles weak?--"By not using them."
What is necessary to make your muscles strong and healthy?--"They must be
used; they must be rested when tired; they must be supplied with pure
blood."
How should the muscles be used?--"They should be exercised in work or
play."
How may they be rested?--"I may rest my muscles by changing position; by
changing my kind of work or play; or by going to sleep."
Explain what you mean by changing your position.--"If I am standing, I must
sit or lie down to rest them; if they are tired, because I have been
sitting too long, I must rest them by standing, walking, or running."
What do you mean by changing the kind of work or play?--"If, in my work or
play, my arms become tired, I must do something in which my arms may rest,
though other parts of my body may be in exercise."
How may you help supply your muscles with good blood?--"By breathing pure
air; by taking wholesome food and drink; and by living in the sunlight."
How does drinking alcoholic liquors hurt the muscles?--"It makes them weak,
and unfit to move the parts of the body."
What wonderful muscle moves without your will?--"The heart."
How does alcohol hurt the heart?--"It makes it beat too fast."
How does "beating too fast" hurt the heart?--"It makes it tired, and
sometimes wears it out." See Appendices on Alcohol and Tobacco.
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[Illustration: THE SKIN (very highly magnified).--(From Walker's
_Physiology_, 1884.)]
A, arteries; V, veins; N, nerves; F, fat cells; E, the outer skin; CL, the
color layer; D, the true skin; PT, a perspiratory tube; HF, a hair and hair
sac; EP, muscles; SG, oil glands; TC, tactile corpuscles; CT, connective
tissue.
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