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Chapter 10 The Muscular System - Anatomy & Physiology

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Terms in this set (20)

  • What are the three types of muscle tissue?

    Skeletal, cardiac, and smooth muscle tissues.

  • What is the primary function of skeletal muscle?

    To produce voluntary movement by contracting and pulling on bones.

  • What characteristic distinguishes cardiac muscle?

    It is involuntary, striated, and has intercalated discs for synchronized contraction.

  • Where is smooth muscle found and what is its function?

    Found in walls of hollow organs; controls involuntary movements like digestion and blood flow.

  • What is a muscle fiber?

    A single muscle cell, multinucleated and elongated, that contracts in response to stimulation.

  • Define the sarcomere.

    The basic contractile unit of a muscle fiber, composed of actin and myosin filaments.

  • What proteins make up the thin and thick filaments in muscle fibers?

    Thin filaments are primarily actin; thick filaments are primarily myosin.

  • What role does calcium play in muscle contraction?

    Calcium binds to troponin, causing tropomyosin to move and expose binding sites on actin for myosin.

  • Explain the sliding filament theory.

    During contraction, myosin heads pull actin filaments inward, shortening the sarcomere.

  • What is the neuromuscular junction?

    The synapse where a motor neuron communicates with a muscle fiber to trigger contraction.

  • What neurotransmitter is released at the neuromuscular junction?

    Acetylcholine (ACh) is released to stimulate muscle contraction.

  • Define muscle origin and insertion.

    Origin is the fixed attachment point; insertion is the movable attachment point of a muscle.

  • What is muscle hypertrophy?

    An increase in muscle size due to growth of individual muscle fibers.

  • What is the role of ATP in muscle contraction?

    ATP provides energy for myosin head movement and detachment from actin during contraction cycles.

  • Describe isotonic muscle contraction.

    Muscle changes length while tension remains constant, producing movement.

  • Describe isometric muscle contraction.

    Muscle tension increases but length remains the same; no movement occurs.

  • What is a motor unit?

    A motor neuron and all the muscle fibers it innervates.

  • What causes muscle fatigue?

    Depletion of ATP, accumulation of lactic acid, and ionic imbalances impair contraction.

  • What is the function of the sarcoplasmic reticulum in muscle fibers?

    Stores and releases calcium ions to trigger muscle contraction.

  • How does creatine phosphate assist muscle contraction?

    It donates a phosphate group to ADP to rapidly regenerate ATP during short bursts of activity.