The Muscular System Muscular System The organ system

The Muscular System

Muscular System The organ system whose primary function is movement and flexibility.

Muscular System muscle - an organ that contracts and gets shorter. This provides the force to move your body parts.

Muscles produce movement and help maintain the position of parts of the body.

Function of Muscles • • Produce movement Maintain posture Stabilize joints Generate heat

Muscle Control • Voluntary muscles- muscles that you are able to control. • Examples are leg and arm muscles

• Involuntary Muscles- you cannot move them consciously. Luckily, they just keep working Examples: the heart

3 Types of Muscles

Skeletal Muscles- Are voluntary and help you move.

Skeletal muscles work in pairs flexor – bends extensor – straightens

Smooth Muscles- include the muscles of internal organs and blood vessels. These muscles move involuntary.

Cardiac Muscle- Found only in the heart and also involuntary.

cardiac muscle

Skeletal Muscle Characteristics Most muscles are attached by tendons to bones.

Why Do I Need Tendons? Tendons attach my muscles to my bone helping my body move.

Feel your tendon right above your heel in the back of your leg.

The Story About Achilles Heel The term “Achilles’ heel” means a person’s vulnerable spot or area. It is derived from the Greek myth of Achilles and his mother Thetis. According to legend, when Achilles was born, his mother, in an effort to make him immortal, took Achilles to the Styx river and dipped him. She held him by one heel. The area where her fingers held him remained dry. As the heel was not touched by the waters of the Styx, it was the one vulnerable place on Achilles became the hero of many battles during the Trojan War. Paris, Prince of the Trojans, shot an arrow in the heel of Achilles. Because the heel was the one spot untouched by immortality, Achilles died. The mythology of Achilles not only gives us the term “Achilles’ heel, ” the tendon connecting the heel to the calf muscles is named the “Achilles” tendon. ”

Muscle Injury Strain – muscle or tendon is overstretched or torn Tendinitis – injured tendon becomes inflamed

Exercise • Exercised muscles are stronger and larger. • Strong muscles can help other organs. • Exercise builds strength and endurance

Resistance • Strengthens skeleton muscles • Work against resistance or weight of an object

Aerobic Steady, moderately steady exercise Strengthens heart and increases endurance

Anabolic Steroids • Used to quickly make stronger, bigger muscles • Cause long term health problems • Can: üDamage heart, liver, and kidneys üCause high blood pressure üCause sterilization üCause emotional problems