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Based
on morphological shape, and location of work systems in the body, muscles are
divided into three, namely striated muscle, smooth muscle, and heart muscle.
Also called striated muscle or muscle skeletal muscle fiber cross. These
muscles work under consciousness. In striated muscle, fibrils-fibrilnya have
transverse lines dark (anisotrop) and light (isotrop) arranged criss-hose.
Layer of fibrous connective tissue covering every muscle and into the inside to
coat the fasikel. This network channeling of nerve impulses and blood vessels
into the muscle and mechanically transmit power from one end of the contraction
of muscle to the other end.
Smooth
muscle is also called involuntary muscle or muscle tool in (visceral muscle).
Composed of smooth muscle cells - spindle-shaped cells smooth. Each - each cell
has one core that is located in the middle. Smooth muscle contraction is not
according to the will, but are supplied by autonomic nerves. Factors that
affect visceral smooth muscle contraction is certain hormones, local metabolic
intermediate produced in the surrounding muscle, mechanical stretch, and some
types of drugs. Cardiac muscle is a combination of skeletal muscle and smooth
muscle, arranged in a pattern miofilamen regular pemitaan that berlurik heart
muscle. Unlike skeletal muscle, some calcium ions are released and used to
trigger a contraction derived from the extracellular fluid, as a result of the
heart muscle becomes very sensitive to the imbalance of calcium in body fluids.
Skeletal muscles always work in
groups and not alone. Some muscles contract in a
group while the other group relaxes. The nature of work divided into
antagonistic muscle and synergistic. From the results of research and
observations with the electron microscope and X-ray diffraction, Hansen and
Huxly (l955) put forward the theory of muscle contraction called a model of
sliding filaments. This model states that contraction based on the existence of
two sets of filaments in the contractile muscle cells that form the actin
filament and myosin filament .. Stimulation received by acetylcholine causes
shrinking aktomiosin (contraction).
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