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We can raise an arm, turn a head, crouch and
then jump up again, thanks to the muscles attached to the bones.
The shortest muscles is in the ear.
The longest are those of the legs.
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Muscles are long fibres. Just like elastic
bands, they stretch or reduce making the bones move.
Biceps swell and pull along the arm-bone, in order to bend the arm. Triceps
extend. To stretch the arms, biceps extend the triceps swell pulling the
forearm-bone. Touch one of your biceps and bend your arm: you'll realise that
your muscle is working. |
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HEART
The heart is an important organ. It is a muscle that never stops beating,
even at night time. When it stops, the body stops living. Your heart is
not bigger than your fist. At each heartbeat, blood is pumped at every
part of the body. On the way back, blood enters the heart, to be sent to
the lungs. |
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