Unit 2 part 2

    Cards (15)

    • Other factors influencing force generation (2)
      Muscle environment (temp, ph, hydration, energy supply)
      Muscle fiber type and muscle architecture ( connective tissue attachement influence force transmission)
    • Primary factors influencing force generation (3)
      Length of the muscle fiber
      Frequency of stimulation (twitch vs tetanus types) (neural effect)
      Number of muscle fibers that have been stimulated (neural effect)
    • Tension types
      Active: generated by active mechanisms like cross bridge cycling
      Passive: generated when muscle is stretched beyond its resting length due to elastic elements within the muscle/tendon tension arises in the absence of muscle contraction
    • How greater ap frequency gives greater peak tension

      Muscle twitch: troponin to shift cuz of calcium release which goes back to SR almost immediately after it released
      Tetanic contractions: Aps are sent before calcium can return to SR so tropomyosin doesn't shift back resulting in my myosin binding sites, more time for cross bridge cycling and finally greater muscle tension
    • Tetanus
      A maintained muscle contraction in response to repetitive stimulation
      Motor units are recruited on a Rotating basis
      Unfused: the muscle fiber has time to partially relax between contraction/stimuli
      Fused: the muscle fiber does not have time to relax between contraction/stimuli resulting in maintained muscle tension
    • Summation
      The increase in muscle tensions arising from successive action potentials
    • Frequency tension relationship
      Positively related
      AP last 1-2ms generated tension can last over 100ms
      The closer the action potentials the greater the resulting peak tension
    • As load increases (3)
      The less the muscle can shorten
      The slower the shortening velocity d/t
      The longer the latent period
    • Isotonic vs isometric
      Isotonic is concentric so muscle tension is greater than the load which results in shortening the muscle length
      Isometric is when the muscle tension and load are equal so there is no change in muscle length
    • Factors effecting changes in muscle length (5)
      Weight/force of the load
      Amount of force generated by the muscle
      Initial length of the muscle fiber
      Frequency of stimulation
      Number of motor units recruited
    • Load
      The force exerted on the muscle by an object (usually its weight)
    • Muscle tension
      The force exerted on an object by a contracting muscle
      Can be created by force muscle
    • Eccentric contraction
      muscle lengthens
    • Isometric contraction
      Tense muscle in steady position
    • Concentric contraction
      Muscle shortens
    See similar decks