The Muscular System

The muscular system works with the skeletal system You have approximately 650 muscles in your body.

Functions of the Muscular System allows your body to move gives shape to your body maintains your posture (standing or sitting)

Muscle Structure muscles cells are called muscle fibers groups of muscle fibers are wrapped together inside a special covering made of connective tissue. bundles of muscle fibers are grouped together to form muscles

Muscle Structure (Cont.) muscles are living organs that require energy, oxygen, food, and other nutrients blood vessels and nerves run through muscles to provide these requirements.

Main Categories of Muscles Voluntary You can control examples: arms, legs, hands, face Involuntary You don’t have control, they move automatically examples: heart, lungs

Three Types of Muscles

Muscle Movement Tendons are flexible connective tissue that connects muscles to bones. Muscles work in pairs to PULL the bone in a certain direction. One part of the muscle pair is called the flexor and the other muscle is known as the extensor. Example: biceps -flexors triceps - extensors

The flexor muscle contracts (shortens) to bend the bone at the joint. The extensor muscle contracts to extend the bone Example: biceps –flexors triceps - extensors

Muscle Maintenance Physical activity and eating a variety of nutritious foods will keep your muscles healthy and strong Kids should not lift weights so that they can look bigger and stronger. Lifting heavy weights can be dangerous to kid’s muscles and tendons.

Steroid Use Some people take illegal drugs to get muscle fast. These artificial hormones can cause serious health problems

Muscular System Problems Strain A pain in the muscle caused by: - putting too much pressure on a muscle -moving it in the wrong direction -pushing the muscle too far You can reduce the risk of a strain by stretching before you exercise. This helps get your blood circulating to the muscle.

Cramp Caused when a muscle contracts involuntarily Can be caused by: - not warming up the muscles before exercising - too much exercise - not enough oxygen to that muscle

Muscular Dystrophy A genetic disorder that weakens muscles The body can not build proteins needed for healthy muscles Gradually lose the ability to do simple tasks such as walking or sitting

Cerebral Palsy Disorder that affects the way the brain communicates to the rest of the body Results in trouble controlling muscles

Videos Bill Nye Bones and Muscles 20:37 Kids Health Muscular System 7:07 Kids Health How Muscles Work 5:49 Muscular System – Our Muscles – make me a genius 5:37 BrainPOP animation about Duchene Muscular Dystrophy 4:13 Living with Muscular Dystrophy by Arnold 5:36 Cerebral Palsy: Ira’s Story 4:40