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Muscle Contraction Essay

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Muscle Contraction Essay
Muscle Contraction
Helpful links:
Diagrams: http://themedicalbiochemistrypage.org/muscle.php http://classes.midlandstech.edu/carterp/Courses/bio210/chap09/lecture1.html
Good explanations: http://science.howstuffworks.com/life/human-biology/muscle2.htm
Quiz: http://www2.muw.edu/~jfortman/220practst2.html
Flashcards: http://quizlet.com/17858377/physiology-ch-8-muscles-flash-cards/ http://quizlet.com/16553525/quiz-4-flash-cards/ http://quizlet.com/19801622/muscle-contraction-flash-cards/

1 What is meant by the skeletal system?
The skeletal system is charge of proving movement, protection, and support. In terms of the muscular system, the skeletal systems functions as a lever
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An actin myofilament is actually composed of what three different molecules? * Troponin - When Calcium binds to troponin, it changes shape, which moves tropomyosin away. This uncovers the actin binding site, which allows myosin to bind to actin and begin contraction. * Tropomyosin - Covers the myosin binding sites on actin. * G-actin 11. Myosin molecules make contact with actin via what structure?
Cross-bridges - The chemical bond myosin molecule forms with the actin molecule 12. What is the contractile unit of skeletal muscle?
Myofibrils - Makes up striated muscle fiber. 13. What is the difference between an A-band and an I-band? * A-band: A bands are the dark areas where myosin, and actin overlap. * I-band: I bands are the light areas that contain only actin. 14. What is the significance of the triad in muscle contraction?
Once a triad has been reached, an action potential triggers the release of Ca2+ from the cisternae of the sarcoplasmic reticulum. This causes a reaction where Calcium ions binds to troponin, which helps set off the contraction. 15. Muscle contraction requires energy stored in what molecule?
ATP.
16. What physiological events occur during the lag phase of muscle
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24. What causes treppe to occur?
Treppe occurs because calcium ions become more available. As they become available, more binding sites start opening, and this reflects the warm-up stage of a muscle. 25. How does treppe differ from multiple wave summation? * Treppe: Treppe occurs when frequency and strength of the stimulus are held constant. * Wave summation: Wave summation is when the frequency of the stimulus is increased. 26. What is muscle tone?
Muscles exhibiting slight contraction, even when at rest, which keeps muscles firm, healthy, and ready to respond. 27. What is the difference between complete and incomplete tetanus? * Complete tetanus: Muscles do not get to rest between stimuli. * Incomplete tetanus: Muscles get to rest slightly during stimuli. 28. What causes physiological fatigue?
Shortage of ATP. 29. What is the difference between physiological and psychological fatigue? * Physiological fatigue: The muscles run out of their ATP reserves. * Psychological fatigue: The muscles have not fatigued, but the brain perceives that additional work is not possible. 30. What causes rigor

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