The muscular system is responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up roughly half of a person's body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves

2. OVERVIEW OF
MUSCLE
STRUCTURE

3.  Muscle : The word muscle is derived from latin word mus means
mouse.
 So the structure of muscle is somewhat like a mouse .
 Definition: A band or bundle of fibrous tissue in a human or animal
body that has the ability to contract , producing movement in or
maintaining the position of parts of the body.

5.  Muscle is the tissue of the body which primarily function as a source of
power.
 There are three types of muscle in the body .
 Skeletal muscle;Responsible for moving extremities and external areas
of the body .
 Cardiac muscle :Heart muscle is called cardiac muscle.
 Smooth muscle :Muscle present in the walls of arteries,intestine and
gut.

6.  STRUCTURE OF MUSCLE:A muscle consist of many tissues bundle
together and surround by Epimysium
 Epimysium : It is a tough connective tissue similar to cartilage .The
epimysium surrounds bundles of nerve cell that run in long fibers
fascicles .
 A bundle of skeletal muscle fiber surrounds by perimysium.
 Perimysium:This layer allow nerves and blood to flow through the
individual fibers .Each fiber is then wrapped in an
 endomysium; another protective layer.These layers and bundles allow
different parts of muscle to contract differentily.

8.  Contractile elements of muscle:
 Muscle fiber is composed of many myofibrils.A myofibril contain
contractile unit called sarcomere .Sarcomere run adjacent to one another
down the length of myofibril.
 Each sarcomere consist of alternating thick and thin protein filaments .The
muscle contacts when these filament release past each other.
 The thick filaments are myosin which are anchored at the center of
sarcomere called M line.
 The thin filaments are composed of protein actin which are anchored to Z
Line,on the outer edge of sarcomere.