Ch. 11 c Twitch/contractions (lecture)

  1. What is a twitch?
    A quick cycle of contraction and relaxation
  2. What contraction involves a change in muscle tension, but not muscle length?
    Isometric contraction (iso=same metric=length). ex. holding a book in your hand, then adding another book but not moving it.
  3. What contraction involves a change in muscle length, but not tension (weight on muscle)?
    Isotonic contraction (iso=same tonic=tension)
  4. What are the two forms/directions of isotonic contractions?
    • Concentric (muscle shortens) ex. arm curls
    • Eccentric (muscle extends) ex. lowering arms
  5. Sources of ATP: What is Aerobic respiration?
    With enough oxygen; glucose is converted into ATP
  6. Sources of ATP: What is Anaerobic respiration?
    • Without enough oxygen, backup systems are used: Creatine phosphate contributes to conversion of ADP to ATP. Also oxygen is taken from myoglobin. These need to be replenished after exercise
    • Stored ATP is also a source of ATP
  7. What are some reasons for muscle fatigue?
    • ATP synthesis slows, ability of sodium-potassium pump to regulate RMP drops
    • Lactic acid lowers pH of sarcoplasm
  8. What is maximum oxygen uptake?
    The peak/plateau of a person’s oxygen consumption
  9. What are type one slow-twitch fibers?
    • Fatigue resistant fibers, darker color
    • Relies on aerobic respiration and has a long twitch
    • Ex. postural muscles of back
  10. What are type two fast-twitch fibers?
    • Paler appearance due to lack of capillaries and other nutrient-giving bodies
    • Uses glycogen for energy and rapid ATP use.
    • Ex. Calf muscles (though is a mix with slow-twitch)
  11. What is resistance training?
    • Muscle contraction against a load
    • Muscles synthesize more myofilaments, making muscles bigger
  12. What is endurance training?
    Improves fatigue resistant muscles, makes slow twitch fibers make more mitochondria which means more ATP
Card Set
Ch. 11 c Twitch/contractions (lecture)
Twitch contractions questions