Disorders Of Muscles And Bones
Categories:
OUR TELEPHONE EXCHANGE AND ITS CABLES
Sources:
A Handbook Of Health
The Muscles and Bones Have Few Diseases. Considering how complex it
is, and the never-ceasing strain upon it, this moving apparatus of ours,
the nerve-bone-muscle-machine, is surprisingly free from disease. The
muscles, though they form nearly half our bulk, have scarcely a single
disease peculiar to them, or chiefly beginning in them, unless fatigue
and its consequences might be so regarded. They may become weakened and
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wasted by either lack or excess of exercise, by under-feeding, or by
loss of sleep; but most of their disturbances are due to poisons which
have got into the blood pumped through them, or to paralysis or other
injuries to the nerves that supply them.
The muscles of an arm, for instance, which has been lashed to a splint,
or shut tightly in a cast for a long time, waste away and shrink until
the arm becomes, as we say, just skin and bone; and the same thing
will happen if the nerve supplying a muscle, or a limb, is cut or
paralyzed.
The bones have more diseases than the muscles, but really comparatively
few, considering their great number and size, and the constant strain to
which they are subjected in supporting the body, and driving it forward
and doing its work under the handling and leverage of the muscles. Most
of their diseases are, like those of the muscles, the after-effects of
general diseases, particularly the infections and fevers, which begin
elsewhere in the body; and the best treatment of such bone diseases is
the cure and removal of the disease that caused them.
Repair of Broken Bones. If bones are broken by a fall, or blow, they
display a remarkable power of repair. The skin covering them
(periosteum) pours out a quantity of living lime-cement, or
animal-mortar, around the two broken ends, which solders them together,
much as a plumber will make a joint between the ends of two pipes. This
repair substance is called callus. The most remarkable thing about the
process is that, when it has held the two broken ends together long
enough for them to knit firmly--that is, to connect their blood
vessels and marrow cavities properly--this handful of lime-cement, which
has piled up around the break, gradually melts away and disappears; so
that, if the ends of the bone have been brought accurately together, you
can hardly tell where the break was, except by a slight ridge or
thickening.