Page 96 - The Miracle of Electricity in the Body

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THE MUSCULAR SYSTEM THAT
THE MUSCULAR SYSTEM THAT

OPERATES ON ELECTRICAL ENERGY
OPERATES ON ELECTRICAL ENERGY

ou expend energy in reading these lines, in turning the pages
of this book and even just sitting back in your chair. Your
Y skeletal muscles provide this strength and use it wherever
necessary. Various muscles extend to every point in your body and
represent some 45% of the human body’s weight.
Every muscle consists of large numbers of fibers between 0.5 and
14 centimeters (0.2 and 5.5 of an inch) in length and an average 0.1 mil-
limeter (0.0039 of an inch) in diameter. Muscle tissue’s most important
feature is its ability to contract, and its ability to do work increases in
direct relation to its ability to contract. Thanks to this ability, you are
able to drink water, walk, speak, close your eyes and turn your head.
Muscles in the human body are divided into two groups, those
under conscious control (voluntary muscles) and involuntary ones. In
order to activate voluntary muscles, one needs to think and decide.
When you want to climb stairs, for instance, your muscles contract at
the command from your brain and perform the action of lifting your
legs. On the other hand, the working of involuntary muscles does not
depend upon volition. Since the functions of these involuntary mus-