1. How Muscles Work Angela Jiang 2005

2. General Facts There are more than 600 major muscles in the human body. There are three main types of muscles, skeletal muscle, cardiac muscle, and smooth muscle.

3. Parts of Muscles • Muscles connected by a • stratum • Muscle are made of fibers. • Fibers are made of myofibrils. • Fibers are held together by connective tissue

4. Parts of Muscle II • Myofibrils made of alternating dark A bands and light I bands. • Bands in different zones called the H zone • H zone separated by Z line.

5. Parts of Skeletal Muscle • End of the muscle attached to the bone that does not move called origin • End attached to the bone that moves called insertion • Flexible connective tissue called tendon Insertion Origin Tendon

6. Cardiac Muscle • Make up the walls of the heart • Help pump the blood from the heart into the arteries. • Can pump about 5 liters of blood each minute

7. Smooth Muscle • Are usually involuntary muscles • means they do not need a command to move • blinking your eyes is an involuntary movement • Are usually in sheets or layers with one over the other

8. What Happens When Hinged Skeletal Muscles Work • Mitochondria produce energy for the muscle fiber to live • Bands are pulled together forming a bridge for myofibrils. • The muscles pull the tendon causing it to pull the bone • The bone moves Muscle Bone Tendon

9. About Me My name is Angela Jiang, I like to ride roller coasters and make origami. I also play tennis and the piano. My favorite animal is the cat.

10. Bibliography Card Montecastle, Vernon B. Medical Physiology. St. Louse, Missouri, 1980