Download The Muscular System

The Muscular System
LIFE SKILLS SCIENCE
MR. HERMANN
MUSCLES
There are more than
600 muscles in the
human body. These
muscles serve many
different purposes. All
movement in the body
depends on muscle,
they also create heat in
the body.
Muscle types
There are 3 different
types of muscle in
the human body,
they are smooth,
cardiac, and skeletal
muscle. All three
types serve different
purposes
Cardiac Muscle
Cardiac muscle tissue is an
extremely specialized form of
muscle tissue that has evolved to
pump blood throughout the body. In
fact, cardiac muscle is only found in
the heart and makes up the bulk of
the heart’s mass. The heart beats
powerfully and continuously
throughout an entire lifetime
without any rest, so cardiac muscle
has evolved to have incredibly high
contractile strength and endurance.
And because the heart maintains its
own rhythm, cardiac muscle has
developed the ability to quickly
spread electrochemical signals so
that all of the cells in the heart can
contract together as a team.
Skeletal Muscle
Skeletal muscle tissue is
composed of groups of muscle
fibers in an orderly
arrangement. A small muscle
may be only a few bundles of
fibers, while the major muscles
in the body, such as the gluteus
Maximus that forms the bulk of
the buttock, are made up of
hundreds of bundles.
Movement of the skeletal
muscle is under the control of
the brain
Smooth or
Visceral Muscle
Visceral muscle tissue, or smooth
muscle, is tissue associated with the
internal organs of the body,
especially those in the abdominal
cavity. As with any muscle, the
smooth, involuntary muscles of the
visceral muscle tissue (which lines
the blood vessels, stomach,
digestive tract, and other internal
organs) are composed of bundles of
specialized cells capable of
contraction and relaxation to create
movement. If one were to slice
through a muscle diagonally, he
would find that it resembles a
telephone cable.
Muscle Groups
Muscles in the body are
grouped together and work
as a team to perform
movement of the body.
Muscles are strong, but by
working together, its less
strain, and allows them to
not have to work so hard.
We will cover some of the
more prominent groups.
The Hamstrings
Group
The hamstring muscle
group is the group that
is used to bend your leg
at the knee. The
muscles flex and your
knee bends. When the
muscle extend or relax,
the leg will go back
down. This is what is
referred to as negatives.
The Calf Muscles
Both of the muscles in
the calf are responsible
for flexion in the angle
and the knee. These
muscles taper at the
bottom and are
connected to the
calcaneus bone by the
Achilles tendon
The Abdominal
Muscles
The abdominal muscle
groups is made up of many
different muscles. This is
one of the largest groups in
the body. The abdominals
are made up of different
layers of muscles that all
work together in helping
your body move.
Summary
We have covered just a few of the more than 600 muscles in
the body. There are many more that are just as important as
those mentioned in this lesson. All of the systems in our
bodyies are equally important, but each one does a different
essential job. All muscle action is started by nerves in the
brain firing and sending the signals to the specific body part.
This will all be covered in a later chapter.