muscles

    Cards (15)

    • What are muscles made up of?
      Bundles of muscle fibers
    • What is a muscle fiber?
      It is the actual muscle cell
    • What are myofibrils?
      Long thin structures in muscle fibers
    • What are sarcomeres?
      Sections that make up myofibrils
    • What types of filaments are in sarcomeres?
      Myosin and actin filaments
    • Describe the structure of muscles.
      • Muscles are made of bundles of muscle fibers
      • Each fiber is a muscle cell
      • Myofibrils are long thin structures
      • Myofibrils consist of sarcomeres
      • Sarcomeres contain myosin and actin filaments
    • How do muscles contract?
      Sarcomeres get shorter during contraction
    • What is the length range of sarcomeres during contraction?
      Between 2.2 and 3 micrometers
    • What happens to actin filaments during muscle contraction?
      They slide between myosin filaments
    • What is the role of special proteins in muscle contraction?
      They drag the filaments together
    • What are the two types of muscle fibers?
      Slow twitch and fast twitch
    • Describe slow twitch muscle fibers.
      • Slow sustained contraction for long periods
      • Lots of mitochondria
      • High aerobic respiration
      • Many capillaries for oxygen supply
      • Large oxygen and glucose stores
    • Describe fast twitch muscle fibers.
      • Rapid intense contractions in short bursts
      • Few mitochondria
      • Energy from anaerobic respiration
      • Produces lactic acid
      • Tires quickly with little stored oxygen
    • What type of athlete typically has more slow twitch fibers?
      Endurance athletes like marathon runners
    • What type of athlete typically has more fast twitch fibers?
      Sprinters and explosive athletes
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