2. The Muscular System Structure Muscles have tissues that holds muscle cells together that provides elasticity. Muscle tissue also has many contractile protein filaments such as actin and myosin enable muscles to contract. These proteins are found in the cytoskeleton of eukaryotic cells. Skeletal muscle tissues contain muscle fibers that contain small cylindrical structures called myofibrils. Myofibrils have alternating light and dark bands that produce characteristic striped appearance. In the center of each light band is a structure called a Z line and in between two Z lines is called a sarcomere.

3. The Function of the Muscular System Muscle tendons stabilize joints. If you don’t have tendons to hold the muscles together, the bones will pop up. Muscles help you be stable by helping you to stay upright and not fall onto the ground. Muscles also help mobilizing your skeleton by attaching to your bones and help you move around. Muscles produce heat by the tissues in the mitochondria using oxygen and releasing energy. Muscles are part of shaping your body. If you want to gain muscle, then you have to burn all the fat and then gain muscle or maybe if you’re skinny, you just exercise.

4. The Muscle Disease: Muscular Dystrophy Muscular Dystrophy is the effect of a genetic mutation for an extra CTG or CCTG in the muscle protein. Muscular Dystrophy is when your muscles start deteriorating. You will know if a child has Muscular Dystrophy when, the child starts to stumble, waddle, and have difficulty going up stairs or walking on their toes. The child often develops enlarged calf muscles because the muscle tissue gets destroyed and is replaced by fat. Exercising and physical therapy can minimize abnormal and painful positioning of the joints, and Respiratory care, deep breathing, and coughing exercises are recommended. Unfortunately there is no cure for any form of muscular dystrophy but medications and therapy can slow the course of the disease.

5. Survival Rate of M.D

6. Muscular System The sarcomere is first relaxed then stimulates the muscle. When the muscle fiber stimulates released by the nerve cell, the muscle contraction begins Myosin and Actin filaments rub along one another causing them to overlap more The sarcomere gets shorter when the Z lines pull together and then are fully contracted While sarcomere shortens down the length of the muscle fiber.

7. Muscles are attached to bones by tendons. Your muscles are normally around 40-50% of your body weight Muscle pairs move parts of the body by pulling on bones. Sarcomere shorten during muscle contraction. There are muscles in the root of our hair that gives us goose bumps. During muscle contraction, actin and myosin interact. Muscles are attached to bones by tendons. Energy is required for muscles to contract. The muscular system is composed of over 600 muscles that come in a variety of shapes and having different locations, functions, structures, and the way they are contracted. Even when lie down or stand up, you use your muscles to maintain your balance and posture A muscle exerts the greatest force when all of its fibers are contracted

8. Bibliography Internet: http://spiritbody.blogspot.com/2008/04/interesting-facts- about-muscles.html http://kidshealth.org/parent/medical/bones/muscular_dyst rophy.html http://www.webmd.com/parenting/understanding-muscular- dystrophy-treatment Video: http:// www.youtube.com/watch?v=q5MyCwatq6E Books: Johnson, George, and Peter Raven, ed. Muscular System. Unknown. Austin: Holt, 2007. 856-860. Print.