DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.6271#0177
( 151 )
WbfJB a muscle acts, it becomes shorter and thicker ; botlt
its origin and insertion are drawn towards ils middle. The
sphincter muscles are always in action ; and so likewise arc
antagonist muscles, even when they seem at rest. When two
antagonist muscles move with equal force, the part which
they are designed to move, remains at rest ; but if one of the
antagonist muscles remain at rest, while the other acts, the
part is moved towards the centre of motion. The extensor
muscles are generally weaker than the flexors: hence the
most natural situation, in which all the powers maintain
a just equilibrium, is that which our limbs take during
sleep. The middle state, between flexion and extension^
we preserve, the longest lime without fatigue. Ties prepon-
derance of the flexor muscles arises from their fibres being
more numerous than the extensors ; their insertion into bones
is farther from the centre of their motions, under an angle
more open, and which increases in proportion as the limbs
are in a state of flexion.
The irritability of muscles destined to perform voluntary
motions, is in a direct ratio of the number and magnitude of
the nerves and arteries, distributed in their structure. Tiie
tongue receives the greatest supply of nerves, and. of all
other contractile organs, is the mo^t subject to vo'itio'.;.
All the muscles of living animals are constant!) endeavour-
ing to shorten themselves.
When a muscle is divided, it contracts. If a muscle be
stretched to a certain extent, it contracts, and endeavours to
acquire its former dimensions, as soon as the stretching cause
is removed : this takes place in a dead body, in muscles cut
out of the body, and also in parts not muscular, and is called
by the immortal Haller vis morttut, and by some tis ela?.tica.
H -t
WbfJB a muscle acts, it becomes shorter and thicker ; botlt
its origin and insertion are drawn towards ils middle. The
sphincter muscles are always in action ; and so likewise arc
antagonist muscles, even when they seem at rest. When two
antagonist muscles move with equal force, the part which
they are designed to move, remains at rest ; but if one of the
antagonist muscles remain at rest, while the other acts, the
part is moved towards the centre of motion. The extensor
muscles are generally weaker than the flexors: hence the
most natural situation, in which all the powers maintain
a just equilibrium, is that which our limbs take during
sleep. The middle state, between flexion and extension^
we preserve, the longest lime without fatigue. Ties prepon-
derance of the flexor muscles arises from their fibres being
more numerous than the extensors ; their insertion into bones
is farther from the centre of their motions, under an angle
more open, and which increases in proportion as the limbs
are in a state of flexion.
The irritability of muscles destined to perform voluntary
motions, is in a direct ratio of the number and magnitude of
the nerves and arteries, distributed in their structure. Tiie
tongue receives the greatest supply of nerves, and. of all
other contractile organs, is the mo^t subject to vo'itio'.;.
All the muscles of living animals are constant!) endeavour-
ing to shorten themselves.
When a muscle is divided, it contracts. If a muscle be
stretched to a certain extent, it contracts, and endeavours to
acquire its former dimensions, as soon as the stretching cause
is removed : this takes place in a dead body, in muscles cut
out of the body, and also in parts not muscular, and is called
by the immortal Haller vis morttut, and by some tis ela?.tica.
H -t