1. A skeletal muscle cell is also referred to as?
    Muscle Fiber
  2. Each muscle fiber is formed during development by the fusion of number of _____________ , ___________ , cells known as  ______________.
    • Undifferentiated
    • Mononucleated
    • Myoblasts
  3. Satellite Cells
    Location: Between the plasma membrane and surrounding basement membrane.

    Function:Become active in response to strain or injury and undergo mitotic proliferation. Daughter cells divide into myoblasts which can fuse with or form new muscle fibers.
  4. Hypertrophy
    Hormones involved?
    Occurs when?
    • Hormones involved: GH & Insulin etc
    • Function: When there is much of a loss of muscle tissue.

    Example: Working out lifting weights
  5. The term muscle refers to....
    a number of muscle fibers bound together by connective tissue
  6. What has striated pattern?
    Skeletal and Cardiac Muscles!
  7. Thick and thin filaments are part of smaller, cylinder bundles called _____________
  8. Most of the cytoplasm of a fiber is filled with ________
    Myofibrils which are made up of ACtin & Myosin
  9. One Z-Band to the next Z-Band is known as?
    Held together by?
    • Sarcomere
    • Held together by proteins, Titin and nebulin
  10. Where are I-Bands found?
    Where there is no Myosin Filaments!
  11. A-Band, what does it consists of?
    Myosin, Start to finish = A-Band
  12. Which muscles are multinucleated?
    Skeletal Muscle are multinucleated
  13. Each myofibril is  wrapped by.......
    Sarcoplasmic reticulum
  14. Myosin heads have an actin binding site and an ATPase site that binds to ______
  15. Actin structure consist of:
    2 strands.....
    Binding sites are inhibited by ________
    ______ has a ______ molec. for every seven actin subunits.
    2 Strands, in a double helix of actin molecules, each has a myosin-binding site.

    Binding sites are inhibited by presence of tropomyosin

    Tropomyosin Trponin
  16. Slow-oxidative (Type 1) fibers Red
    Have a low ______ _____ activity....
    Has low ___-__ activity with high ___ capacity..
    Has small _____ w/ many blood vessels.....

    USED FOR......... and have _____ thus red
    • Have a low GLYCOTIC ENZYME activity....
    • Has low MYOSIN_ATPase activity with high OXIDATIVE  capacity..

    Has small DIAMETER w/ many blood vessels.....

  17. ______ has calcium binding sites
  18. Fast Oxidative (Type IIa) FIbers - Red

    Has high _______-___ activity
    Has high _______ capacity
    Intermediate _____ w/ many blood vessels
    High in ________
    Intermediate ________ enzyme cpacity
    Intermediate GLycogen content
    Fast ___________
    • Has high MYOSIN-ATPase activity
    • Has high OXIDATIVE capacity
    • Intermediate DIAMETER w/ many blood ves.
    • High in MYOGLOBIN
    • Intermediate GLYCOLYTIC enzyme capacity
    • Intermediate GLycogen content
  19. Fast Glycolytic (Type IIb) FIbers - WHITE
    Low in _______  but high in ________
    Fatigues very ___________
    High _____-ATPase activity
    High ______ activity
    Produces the most ______ of the three.
    • Diamter = LARGE FIBERS
    • Low in MYOGLOBIN but high in GLYCOGEN
    • Fatigues very QUICKLY
    • High MYOSIN-ATPase activity
    • High GLYCOLYTIC capacity
    • Produces the most TENSION of the three.
  20. What three things control for the strength of a muscle contraction?
    • Number of stimuli/sec
    • Diameter of fiber
    • Length of fiber before contraction.
  21. # of fibers (motor units) contracting depends on what 4 things?
    • Number of fibers/motor unit
    • KInd of fibers in motor unit
    • # of action potentials
    • Recruitment
  22. Causes of fatigue in muscle:
    In t-tuble...
    Depletion of cell nutrients...
    • Change of ionic concentration in t-tubule :
    • (K+) or lactic acid
    • Depletion of cell nutrients... glycogen stores r depleted
  23. Muscles need to be stimulated by....
    Motor units
  24. Disuse Atrophy:
  25. Denervation Atrophy
  26. Use of muscles causes.....
    Endurance excercises causes more ____ fibers.
    Power excercises (weights) cause more __ fiber
    • Hypertrophy
    • Endurance excercises causes more oxidative fibers
    • Power excercises (weights) cause more glycolytic fibers
  27. WHat are myofibrils made up of?
    Actin an d myosin
  28. Myosin heads aka ______ have an _____ binding site and ____ site that binds to ATP
    • Cross bridges
    • Actin
    • ATPase
  29. Actin structure...
    double helix of _____ molecules each has ___ binding site.

    Binding sites are inhibited in pres. of ____ which has ______ for ever _ actin subunits.
    2 strands in doubl helix of actin molecules each has myosin binding site.


    • Troponin
    • 7
  30. What are sarcomeres of skeletal muscle held together by?
    • Titin
    • Nebulin
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