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Muscular system notes
Health 2
 The job of the muscles is to contract and pull the bones to
which they are anchored allowing one to move about, lift,
and carry items. They also function to pump your blood,
move food through the digestive system, and control the air
that moves in and out of your lungs.
 The typical male body contains approximately 640 muscles,
which compose nearly 40% of the body weight.
 A typical muscle spans a joint and tapers at each end into a
fibrous tendon anchored to a bone.
 The names of muscles reflect their shape, the bones to which
they are attached, or the function that they perform.
There are three types of muscle tissue:
 Skeletal: show pronounced strips and bands work to together
to allow movement.
 Smooth: These are the only tapered muscle cells with dark
nuclei, and are found in the digestive tract allowing the body
to perform peristalsis.
 Cardiac: The muscle fibers of the heart which are short and
striated to allow for electrical conductions.
Muscle fibers consist of densely packed groups of hugely
elongated cells known as myofibers. These fibers contain thick and
thin myofilaments made up mainly of proteins actin and myosin.
Oxygen is needed to fuel the muscle contraction, and calcium is
needed to allow the muscle to relax.
Problems associated with the muscular system:
Strain: stretching or tearing of muscle fibers.
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Very common
Usually occur in large muscle groups
Result from over exertion
Need rest to heal
Ice should be applied for the first 48 hrs
Muscle cramp: muscle tissue contracts spasmodically and
involuntarily.
 Muscle feels tense, knotted, and painful
 May occur from overuse
 Treat by gently stretching the muscle and firmly massaging
the knot out
Muscular dystrophy: crippling disease characterized by a
progressive wasting away of skeletal muscles.
 Usually inherited
 Muscle cells are unable to function properly and are replaced
by fatty tissue.
 Symptoms vary depending on the part of the body that is
affected.
 May experience muscle weakness, and difficulty standing or
walking.
 Early detection is critical
 Muscle weakening can be delayed
 Cannot be cured
Care for muscles:
 The more they are used the more efficient and strong they
become.
 Regular exercise with stretching lengthens and strengthens
the muscles and tendons.
 Exercise can promote coordination and decrease falls.