Anatomy Ch 9

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Anatomy Ch 9
2012-10-23 14:58:25

Anatomy Ch 9
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  1. What is a sarcomere?
    • The smallest contractile unit of a muscle, from z disc to z disc.
    • The functional unit of a myofibril.
  2. What type of proteins are actin and myosin in skeletal muscle?
    Contractile proteins.
  3. What type of proteins are troponin and tropomyosin?
    Regulatory proteins.
  4. What is a sarcolemma?
    The plasma membrane of the skeletal muscle cell.
  5. What ion is stored in the sarcoplasmic reticulum?
    Calcium ions
  6. What is a fascicle?
    Bundles of muscle fibers surrounded by connective tissue.
  7. What is the endomysium?
    Connective tissue surrounding each individual muscle fiber.
  8. What is perimysium?
    Connective tissue surrounding each fascicle.
  9. What is epimysium?
    Connective tissue surrounding the entire muscle. Outermost.
  10. What type of filaments contain actin?
    Thin filaments
  11. What type of filaments contain myosin?
    Thick filaments
  12. Which filaments have the active sites located on them?
  13. What is a cross bridge?
    • Formed when myosin heads link with the binding sites of actin.
    • (Linking together of thick and thin filaments)
  14. What type of protein is titin?
    Structural protein
  15. What ion does troponin bind to in skeletal muscle?
    Calcium ions
  16. What is anchored in the z discs?
    Actin and titin
  17. Where are calcium ions stored in a relaxed skeletal muscle?
    • Sarcoplasmic reticulum
    • (cytosol)
  18. What are t (transverse) tubules?
    Invaginations (infoldings) of the sarcoplasm.
  19. What travels down the T tubules?
    Action potentials.
  20. What is acetycholine?
    The neurotransmitter used in skeletal muscle contraction.
  21. What type of muscle contains dense bodies?
    Smooth muscle
  22. What is calsequestrin?
    A calcium binding protein, helps store high concentrations of calcium in SR
  23. What type of muscle uses calmodin to bind calcium?
    Smooth muscle
  24. What is the sliding filament mechanism?
    • Power stroke/Recovery stroke
    • Thin filaments slide past thick ones, overlap slightly creating contraction.
  25. What is a isometric contraction?
    Tension builds in muscle, but it never shortens or lengthens.
  26. What is concentric isotonic contraction?
    The muscle shortens as it does work.
  27. What is eccentric isotonic contraction?
    The muscle generates force as it lengthens.
  28. What is elasticity of muscle?
    The ability of muscle tissue to return to it's original length and shape.
  29. What is extensibility of muscle?
    The ability of a muscle to stretch w/o being damaged.
  30. What is the neuromuscular junction?
    Where nerves meet a muscle.
  31. What is the motor end plate?
    The area of the sarcolemma containing ACh receptors.
  32. What is a muscle twitch?
    • A motor unit's response to a single action potential of its motor neuron,
    • Latent period, Period of contraction, Period of relaxation.
  33. What is unfused tenatus?
    A sustained but quivering contraction due to increase frequency of contractions.
  34. What is fused tenatus?
    Reach of state where thereĀ is no muscle relaxation; smooth sustained contraction.
  35. What muscle type has intercalated discs?
    Cardiac muscle.
  36. What molecule is hydrolyzed to provide energy for muscle contraction?
  37. Where are calcium ions stored during relaxation of muscles?
    • Sarcoplasmic reticulum
    • (Cytosol)
  38. Where are calcium ions released into when muscle contractions occur?
  39. What is the creatine phosphate system?
    ATP source for immediate 10-15 secs of activity. (Direct phosphorylation)
  40. What is the glycolysis-lactic acid (anaerobic) system?
    ATP source after CP, splits glucose into pyruvic acid, 30-60 secs anaerobic.
  41. What is cellular respiration?
    Metabolic process in which ATP is produced.
  42. What strength of contraction results from optimum overlap of muscle filaments?
  43. What strength of contraction results from minimal overlap of muscle filaments?
  44. What strength of contraction results from too much overlap of muscle filaments?
  45. What are slow oxidative muscle fibers?
    Red, good fatigue resistance, lots of myoglobin, smallest in diameter.
  46. What are fast glycolytic muscle fibers?
    White, little ,myoglobin, fatigue quickly, large in diameter.