Helena weekly herald. [volume] (Helena, Mont.) 1867-1900, 1883-11-29
Muscles Of the Skin.
Manufacturer and Builder. |

In certain animals very abundant mus
cular layer is developed Immediately be-
meath the skin, so that they possess the
power of wrinkling it and shaking it in
order to rid themselves of dust, insects,
etc. In man this is found only in few sit
uations and moderately developed but
the human skin possesses within its struc-
ture certain amount of muscular fbers,
which are of special importance in the
present study of the sebaceous glands.
These muscles in the skin belong to the
class of what are called smooth or unstriped
muscles, which differ from those composing
the mass of muscles of the limbs, etc, in
that they are not controlled by the will
they are therefore called involuntary mus
cular fibers. These are, of course, ex-
tremely small, but are readily seen by the
microscope. They extend from near the
end or deeper portion of each hair follicle,
in slanting direction, and terminate or
are inserted near the outer surface of the
corium or true skin. The name given to
these muscles is drrectOr pill, or in the
plural drrectOres pii0rum, so called because
when they contract they cause the hair to
stand more or less erect and to protrude
little from the skin; thus in the cat, when
excited or enraged, all the hairs become
erect and bristling. The action of these
muscles may well be observed in man in
what is called goose skin," when from ex-
posure to cold, or sometimes from emotion
al causes, the skin may be observed to be
thrown into numerous projections. This
condition may be readily observed on en-
tering warm bath; if the portion not i'm
mersed gets little chilled, and if the sur
face be yet dry, the fine hair on the arm
may be seen to rise and stand more or less
erect, and as the condition subsidies, the
masses of hair sink to their former position
all together. This may be repeated sew
eral times. all rising and falling together,
like field of grain under the wind. 1t
was to this action that Shakespeare referred
in the utterance of the ghost in Hamlet, in
the lines
81 could tale unfold. whose lghtest word
Would harrow up thy soul, freeze thy young
blood
Make thy two eyes, Hike lstars, start from their
spheres;
Thy knotted and combined locks to part,
And each particular hair to stand on end,
Like quilts upon the fretful porcupine."
But these muscles have another action
which is very important, and that is the
emptying of the sebaceous glands. These
their own, and their secretions, which are
constant, oozes out upon the surface. Now
where there are large hairs, as upon the
scalp and beard, these muscles more or less
embrace the sebaceous glands, and by their
contraction they empty them from time to
time, and by this means prevent an accu-
mutation or prevent the openings from be-
coming clogged.
On the face, back and chest, however
where we have acute development, and
where these glands are apt to become
plugged up with the black specks SO often
seen. these muscles are almost entirely alb
sent, and the secretion, having no particu-
larly expulsive force, readily becomes i'm
pacted, and, if at all hard, fails entirely of
gaining exit.