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muscoli

Muscoli, the Italian word for muscles, are contractile tissues that enable movement, stabilize joints, and generate heat. In humans they are classified into three main types: skeletal muscles, smooth muscles, and cardiac muscle. Skeletal muscles attach to bones via tendons and produce voluntary movements; they are striated and organized into fibers bound into groups. Smooth muscles occur in the walls of hollow organs and blood vessels, driving involuntary motions such as peristalsis and vasoconstriction; they are non-striated. Cardiac muscle forms the heart walls and contracts rhythmically to pump blood; it shares properties with both skeletal and smooth muscle.

Muscle fibers consist of long cells containing myofibrils arranged in sarcomeres. Contraction is driven by the

Muscles adapt to use. Resistance training promotes hypertrophy and strength gains through neural and muscular changes;

sliding
filament
mechanism,
where
actin
and
myosin
filaments
slide
past
each
other,
powered
by
ATP.
Contraction
is
initiated
by
electrical
signals
from
motor
neurons
at
the
neuromuscular
junction,
with
calcium
ions
triggering
cross-bridge
cycling.
Energy
is
supplied
by
ATP
produced
through
aerobic
respiration,
anaerobic
glycolysis,
and
phosphocreatine;
oxygen
delivery
and
mitochondrial
density
influence
endurance.
endurance
training
improves
oxidative
capacity.
Disuse
leads
to
atrophy.
Nutrition,
hormones,
and
age
influence
muscle
mass
and
function,
with
protein
intake
and
vitamin
D
among
contributing
factors.
Understanding
muscles
involves
anatomy,
physiology,
biomechanics,
and
pathology,
including
conditions
such
as
muscular
dystrophies,
myopathies,
and
fatigue
syndromes.