There
are
almost
____________________
muscles
in
the
body
,
which
can
make
up
almost
half
of
your
body
weight
.
Muscles
have
three
main
functions
:
?
____________________
?
Maintaining
____________________
?
Production
of
heat
The
muscular
system
is
also
involved
in
the
movement
of
____________________
such
as
;
?
Blood
?
____________________
?
Urine
Muscles
play
a
part
in
order
to
stand
upright
,
the
fibres
of
some
muscles
create
____________________
and
rigidity
.
Heat
is
created
by
the
movement
generated
by
the
muscles
.
Each
muscle
is
approximately
75%
____________________
,
20%
protein
and
5%
mineral
salts
,
glycogen
and
fat
.
Skeletal
muscles
are
composed
of
bundles
of
muscles
fibres
called
____________________
.
These
bundles
and
muscles
are
surrounded
by
connective
tissue
sheaths
.
The
epimysium
is
the
outer
layer
which
encircles
the
entire
muscle
.
The
perimysium
surrounds
collective
bundles
of
muscles
,
whilst
the
____________________
surrounds
the
individual
muscle
fibre
.
This
layer
contains
blood
capillaries
that
supply
blood
containing
oxygen
and
nutrients
,
and
remove
waste
products
.
The
three
main
types
of
muscle
are
voluntary
,
which
is
mainly
attached
to
the
bone
,
____________________
,
which
is
found
inside
the
digestive
and
urinary
tracts
as
well
as
the
walls
of
blood
vessels
,
and
finally
cardiac
,
which
is
only
found
in
the
walls
of
the
heart
.
