Muscular System
Jan 12, 2016
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.