Muscular System

Muscular System

• Muscle tissue has one essential function -- Contraction

• As a result, muscles are responsible for nearly all of the body’s movement and can be viewed as the machines of the body.

Muscle tissue

• Because all muscle cells are elongated, regardless of type, they are called muscle fibers

Muscle Types

• There are 3 types of Muscle tissue

• Skeletal

• Cardiac

• Smooth

Skeletal Muscle Fibers

• Skeletal muscle fibers are packaged into the tissues called skeletal muscles that attach to the body’s skeleton.

• They are always cigar shaped, multinucleate, and the largest muscle fibers in the body

Skeletal Muscle• Skeletal muscle can also be referred to as striated muscle and voluntary muscles

• Striated muscle because of the large stripes that it has

• Voluntary muscle because it is the only muscle tissue that we can control consciously.

Gross Anatomy of Skeletal muscle

• Skeletal muscle fibers are very delicate but they can exert a large amount of force when needed

• This is because of the way they are held together with various types of connective tissue

Gross Anatomy of Skeletal muscle

• On the outside of every muscle fiber is a delicate connective tissue called Endomysium

• Several of these fibers are then bundled together by a connective tissue called Perimysium.

Gross Anatomy of Skeletal muscle

• The bundle of Perimysium wrapped together is called a fassicle

• Many fassicles are then wrapped together to and bound by Epimysium

• Lastly the muscle group is then bound to the bone via strong connective tissue called a tendon.

Tendons• Tendons are just as important as your muscles when looking at the muscular system

• Tendons are responsible for anchoring all muscles to the proper bony projections, usually near joints.

• Because tendons are relatively small in size compared to the muscular counterpart, more can fit near a joint area

Smooth Muscle • Smooth muscle has no striations

• It is involuntarily controlled

• Found in the visceral organs of the body like the stomach, intestines, and esophagus.

• Main function is to propel substances through the body along a definite path

Cardiac Muscle

• Cardiac muscle is found only in one place in the body, the heart

• Cardiac muscle is striated.

• Cardiac muscle is involuntary.

Muscle Functions

• The muscles of the body play four important roles:

• Produces Movement

• Maintains Posture

• Stabilizes Joints

• Generates Heat

Producing Movement• Just about all movements of the body are a result of muscular contraction

• There are several types of movement that muscles are responsible for:

• Locomotion, Manipulation, and moving nutrients and fluids though the human body.

Maintaining Posture

• The muscles of the body are responsible for our body’s posture

• They are constantly making tiny adjustments so that we can sit up, lie down, or stand the way that we choose too.

Joint Stabilization

• Muscles aid in the stabilization of the joints of the skeletal system

• The tendons specifically are key in stabilizing these joints

Generation of heat• Heat is a by product of muscle movement

• Your skeletal muscles make up approximately 40% of your body mass

• Thus, your skeletal muscles help maintain your normal body temperature of 98.6 degrees Fahrenheit.