The study of muscles and supporting structures called
miologi. We can learn about muscle macroscopically (naked eye) and microscopically
(using a microscope). Every muscle tissue has the ability to contract (shorten)
and relax (longitudinal), this ability make them as a tool motion in human
body. Along with bone and nerve stimulation, the muscles can move. This muscle
cells working in a group not on their own, meaning that the cells of the same
muscle contract to do a job.
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| TYPES OF MUSCLE |
A. SMOOTH MUSCLE (PLAIN MUSCLE)
Smooth muscle is a muscle that is 'involuntary' which
means these muscles work unconsciously / not according to the will. These
muscles contract slowly, but it can work for a long time. Energy usage in
smooth muscle contraction is very efficient.
Smooth muscle cells have one nucleus, located in the
middle. smooth muscle has Spindle-shaped fibers. This muscle is composed of
pointy shaped and elongated cells. Can be seen in the picture.
Examples of organ composed by smooth muscle is
digestive organs such as the esophagus, intestine and colon.
There are two types of smooth muscle based on their
muscle nerve fibers are stimulated to contract, namely:
- Dual Unit / multi-unit Smooth muscle, this muscle requires an external nerve stimulus to contract. Examples of these muscles are the muscles that focus the eye lens and adjust the size of pupil.
- Single Unit (visceral) Smooth Muscle, this muscle does not require an external nerve stimulus to contract, the example of these muscle is found in the layer of hollow organs (viscera).
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| SMOOTH MUSCLE |
B. SKELETAL MUSCLE
Skeletal muscle is the opposite of smooth muscle.
Skeletal muscles work consciously, it means to work according to the will,
every move of skeletal muscle depends on a person's desires.
Skeletal muscle has a lot of cell nucleus, that's
what makes them able to work stronger, but this muscle Easily tired. Easily
tired, means can not do a job continuously without a break. Unlike the case
with the heart muscle. This muscle have a very long cylindrical cells. Known as
the skeletal muscles because it attached to the skeleton. The structure can be
seen in the image below.
Examples of organ composed by smooth muscle are ;
most of the face, extremities, and abdominal wall.
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| SKELETAL MUSCLE |
C. HEART MUSCLE
The heart muscle is usually called the myocardium,
myo meaning muscle, and Cardium means the heart. So as the name suggests, these
muscles are the muscles located in the heart. It can be said that the heart
muscle is a combination of smooth muscle and skeletal muscle.
The shape of the heart muscle cells is similar to
skeletal muscle (long cylindrical but has a nucleus in the center) and its
properties are similar to smooth muscle (work involuntary). These muscles work
continuously without being tired and never rest, the work was not regulated by
the nervous system, but by a system that regulate the heart's electrical flow. This
muscle is found only in the heart, especially form the walls of the ventricles.
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| HEART MUSCLE |
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| 3 TYPES OF MUSCLE AND THEIR CHARACTERISTICS |
