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.

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

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.

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

Types of muscle tissue:

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

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:

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

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.

Muscle examples:

Some of the major muscles that are you responsible for include:

• Tibialis Anterior

• Obliques

• Deltoids

• Forearms

• Gastrocnemius

• Pectorals

• Abdominals

• Triceps

• Gluteals

• Quadriceps

• Sternocleidomastoid

• Latissimus Dorsi

• Trapezius

• Biceps Brachii

• Hamstrings

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