Muscular System

Facts about the Muscular System:

There are approximately 650 skeletal muscles in the human body. Muscle can only act when it gets signals from the nervous system. The release of the signal to control a muscle can be voluntary (controlled) or ^^involuntary (not controlled)^^ from the nervous system.

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Each muscle attaches to the bone at both ends one end is called the insertion and the proximal end is at the other attachment. In muscle contraction, the insert always moves toward the origin. Muscles make up 40% of your total body weight. Muscles cannot push, they must always pull.

Function

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The function of the muscle is to attach to the bone, when the muscle is activated it contracts. When muscles contract it brings the bones attached at each end to the muscle together. This is known as a ^^muscular contraction^^.

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There are three types of muscle contraction, these are including %%Concentric contraction (shortening),%% @@Eccentric contraction (lengthening),@@ and ==Isometric contraction (static)==

Types of muscle tissue:

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There are three types of muscle tissue: These include %%smooth muscle%%, ^^skeletal muscle,^^ and ==cardiac muscle.==

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%%Smooth muscle:%%

Long and spindle-shaped
It’s found in the walls of organs along with hollow cavities
It serves to propel material along the length of cavities. Some examples are the urinary and respiratory systems.
Involuntary. This means that they work without conscious control

==Cardiac Muscle==:

Heart muscle
Involuntary (works without conscious control)
More organized than smooth muscle
It’s pseudo striated
Avg heart rate is approx. 65 bpm

^^Skeletal muscle^^:

It’s also called striated
It’s long cylindrical and striped up in appearance
Makes up the form of the body, usually attaches to the bone via tendons, and crosses a joint
Muscular contraction moves one bone at the joint to produce movement
Characterized by rapid, short-term contraction of strength
Underneath voluntary control

Growth and maturation:

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Muscles can either shrink or grow depending on the load which is placed on the muscle.

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==Muscle hypertrophy== involves an increase in the size of skeletal muscle through a growth in the size of its cells as a result of the increased demand or load placed on the muscle.

%%Muscle atrophy%%: This is defined as a decrease in the mass of the muscle. The decrease in mass of the muscle can be partial or complete wasting away of the muscle. This is experienced when you suffer the loss of demand on the muscle such as an injury, disease, or a lock of gravity (space).

Some other reasons are overall health. Rehabilitation training and sport-related performance.