1. By: Adam Lundquist, Carmela Patriz, DeCarlo Ward “ROTATE, FLEX, EXTEND THE MUSCULAR SYSTEM IS YOUR FRIEND!”

2. The Major Functions of the muscular system: Skeletal muscles contract which moves the body. Skeletal muscles also maintains a person’s posture. Production of body heat which is necessary for homeostasis and maintaining a person’s body temperature. Smooth muscles can move solids and liquids through the digestive track and other secretions from organs. Cardiac muscle makes the heart beat and propels blood throughout the entire body. C

3. Muscle Structures Skeletal Muscle Each muscle is an organ, comprised of skeletal muscle tissue, several connective tissue coverings, nervous tissue that causes it to contract and blood that nourishes it. C

4. Epimysium- Under the outer layer is this layer which is around each whole muscle Perimysium- surrounds individual bundles of fibers called fascicles within each muscle Endomysium- is a fibrous connective tissue layer that covers each muscle cell (fiber) Fascia- Layers of fibrous tissue that surround and separate each muscle - This type of connective tissue extends past the ends of the muscle and gives rise to cord like tendons that are fused to the periosteum of bones. Aponeurosis - Broad sheets of connective tissue that are sometimes connected to muscles Connective Tissue Coverings: D

5. ‒Each muscle fiber is covered by a connective tissue layer called endomysium. ‒ Muscle fiber membrane is the sarcolemma which contains cytoplasm called sarcoplasm. ‒Within the sarcoplasm are many parallel myofibrils. ‒These protein filaments are actually made up of two types; a thicker filament which is mysosin and a thinner filament actin. Muscle Fiber(Cell) C

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7. Relationships with the Neuromuscular Junction The neuromuscular junction is the site where the motor neuron and muscle fiber meet. The muscle fiber membrane forms a motor end plate in which the sarcolemma is tightly folded and where nuclei and mitochondria are abundant. Acetylcholine is a neurotransmitter released from the motor of the neuron. Muscle innervation releases calcium. D

8. Steps: Nerve impulse---acetylcholine is released Muscle impulse Calcium released--- (from sarcoplasmic reticulum) Calcium binds to troponin, changing shape Myosin heads attach to actin Heads pivot, shortening Sarcomere = Contract Sliding Filament Theory ‒Sarcomere shortens when ATP gives energy to myosin because crossbridges of thick filaments (myosin) pull on think filaments (actin). A

9. ENERGY Sources of Energy: Existing ATP in molecule Creatine Phosphate(converting ADP+P to ATP) Glycolysis (without oxygen)-lactic acid Cell Respiration (with oxygen)- need blood supply (hemoglobin) -interrupted=fatigue Myoglobin in muscles stores oxygen for cell respiration A muscle cramp is an involuntarily and forcibly contracted muscle that does not relax. A cramp can involve a part of a muscle, the entire muscle, or even several muscles that usually act together. A very common reason for cramping is dehydration or low sodium. D

10. ENERGY(oxygen debt) When oxygen debt gets to a certain point then muscle fatigue occurs & too much lactic acid builds up due to lack of oxygen D

11. Summation: Muscular Responses This is when the force of individual twitches combines. Recruitment: An increase in the number of motor units being activated. D

12. Muscular Responses Sustained Contraction:Muscle Tone: ‒Summation and recruitment together can produce a sustained contraction of increasing strength. ‒Even when a muscle appears to be at rest its fibers undergo some sustained contraction. This is called muscle tone. D

13. Movements of Muscles EX FLEXION EXENTION PRONATION SUPINATION C

14. Movements of Muscles (cont.) C

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16. Diseases/Disorders This is a group of inherited disorders & can occur in childhood or adulthood and involve weakness in muscles and the loss of muscle tissues over a period of time that can keep getting worse and worse. Some of the types of muscular dystrophy are: Becker muscular dystrophy Duchenne muscular dystrophy Limb-girdle muscular dystrophy, Myotonia congenita Myotonic dystrophy A

17. Diseases/Disorders Fibromyalgia: Fibromyalgia is a common syndrome in which some people can have body- wide pain and some tenderness in their joints, and in muscles, tendons, and soft tissues. It has also been linked to loss of sleep, fatigue, depression and anxiety, and headaches. A

18. Diseases/Disorders Myositis: This is the inflammation of your skeletal muscles (called voluntary muscles) Injuries, infections or an autoimmune disease can cause myositis. Inflammatory Myopathy Focal Myositis A

19. The End ANY QUESTONS?

20. Works Cited Clencoe Hole’s Essentials of Human Anatomy & Phisiology Gretchen Fisher http://www.encognitive.com/node/1127