Skip to main content
Pearson+ LogoPearson+ Logo

Structure of a Skeletal Muscle quiz Flashcards

Structure of a Skeletal Muscle quiz
Control buttons has been changed to "navigation" mode.
1/27
  • What structure is the functional unit of contraction in a skeletal muscle fiber?
    The sarcomere is the functional unit of contraction in a skeletal muscle fiber.
  • What term is used for the plasma membrane of a muscle fiber?
    The plasma membrane of a muscle fiber is called the sarcolemma.
  • What are thin filaments composed of?
    Thin filaments are primarily composed of the protein actin.
  • What is a motor unit composed of?
    A motor unit is composed of a motor neuron and all the muscle fibers it innervates.
  • What causes the striated appearance of skeletal muscle fibers?
    The striated appearance of skeletal muscle fibers is caused by the repeating structure of sarcomeres, composed of actin and myosin filaments.
  • What protein are the thin filaments made of?
    Thin filaments are made of the protein actin.
  • Which of the following describes a transverse tubule (t‑tubule)? A) A structure that stores calcium ions B) A membrane canal that extends into the muscle fiber C) A protein that forms thick filaments D) A connective tissue surrounding muscle fibers
    B) A membrane canal that extends into the muscle fiber
  • Thin filaments are primarily composed of which protein?
    Thin filaments are primarily composed of the protein actin.
  • What is the functional contractile unit of the myofibril?
    The functional contractile unit of the myofibril is the sarcomere.
  • What part of the sarcolemma contains acetylcholine receptors?
    The part of the sarcolemma that contains acetylcholine receptors is the motor end plate.
  • What is the function of t-tubules?
    T-tubules transmit electrochemical signals deep into the muscle fiber to ensure uniform contraction.
  • What structures form a motor unit?
    A motor unit is formed by a motor neuron and the muscle fibers it innervates.
  • Which of the following accurately describes the structure of a muscle? A) Muscle fibers are surrounded by epimysium B) Fascicles are bundles of muscle fibers C) Myofibrils are composed of fascicles D) Sarcomeres are surrounded by perimysium
    B) Fascicles are bundles of muscle fibers
  • What makes up the thick filaments?
    Thick filaments are primarily made of the protein myosin.
  • Which is found in thin filaments but is not a regulatory protein?
    Actin is found in thin filaments and is not a regulatory protein.
  • What is the function of t tubules?
    T tubules function to transmit electrochemical signals deep into the muscle fiber.
  • What protein are the thick filaments made of?
    Thick filaments are made of the protein myosin.
  • What makes up the thin filaments?
    Thin filaments are made up of the protein actin.
  • What makes up the a bands in striated muscle?
    The A bands in striated muscle are made up of overlapping thick and thin filaments.
  • What protein is a thick filament involved with contractions and contains heads to form extensions?
    Myosin is the thick filament protein involved in contractions and contains heads to form extensions.
  • The contractile portion of the thin filament is composed of what protein?
    The contractile portion of the thin filament is composed of the protein actin.
  • Which of the following best describes the term sarcoplasmic reticulum? A) A structure that stores and releases calcium ions B) A membrane canal extending into the muscle fiber C) A protein forming thick filaments D) A connective tissue surrounding muscle fibers
    A) A structure that stores and releases calcium ions
  • Thick filaments are primarily made of which protein?
    Thick filaments are primarily made of the protein myosin.
  • What is the cause of the striated appearance of skeletal and cardiac muscle?
    The striated appearance is caused by the arrangement of actin and myosin filaments in sarcomeres.
  • Which structure in the muscle cell stores calcium?
    The sarcoplasmic reticulum stores calcium in the muscle cell.
  • What is a striation and how does it help muscle cells function?
    A striation is a pattern of alternating light and dark bands in muscle cells, aiding in contraction by organizing actin and myosin filaments.
  • Which of the following surrounds an individual muscle cell? A) Epimysium B) Perimysium C) Endomysium D) Sarcolemma
    C) Endomysium