7.1.1 Structure of Skeletal Muscle

• What type of muscle is skeletal muscle?

  Voluntary
• Skeletal muscles enable coordinated movement.
• Arrange the hierarchical organization of skeletal muscle from smallest to largest:

  1️⃣ Muscle Fibre

  2️⃣ Fascicle

  3️⃣ Muscle
• A muscle fibre is a single muscle cell
• What does a fascicle consist of?

  Bundle of muscle fibres
• The sarcolemma transmits nerve impulses in muscle fibres.
• What does the sarcoplasmic reticulum store and release?

  Calcium ions
• T-tubules facilitate the rapid transmission of action potentials
• Match the level of organization with its description:

  Muscle Fibre ↔️ Single muscle cell

  Fascicle ↔️ Bundle of muscle fibres

  Muscle ↔️ Group of fascicles
• Muscle fibres contain myofibrils for contraction.
• What is the role of a fascicle in muscle contraction?

  Contains multiple muscle fibres
• Each level of muscle organization contributes to the overall function of muscle contraction
• Skeletal muscle contraction is voluntary.
• Which component of skeletal muscle contains actin and myosin filaments?

  Sarcomere
• The sarcoplasmic reticulum stores and releases calcium ions for contraction
• Match the component of skeletal muscle with its role:

  Muscle Fibres ↔️ Contract to produce movement

  Myofibrils ↔️ Contain sarcomeres

  Sarcolemma ↔️ Transmits nerve impulses
• Arrange the steps involved in muscle contraction:

  1️⃣ Nerve impulse reaches the sarcolemma

  2️⃣ Calcium ions are released

  3️⃣ Actin and myosin filaments slide

  4️⃣ Muscle fibre contracts
• What is the basic unit of skeletal muscle contraction?

  Sarcomere
• Muscle fibres are single muscle cells with multiple nuclei
• Sarcomeres contain actin and myosin filaments, which cause muscle contraction.
• Match the component with its role:

  Muscle Fibres ↔️ Contract to produce movement

  Myofibrils ↔️ Contain sarcomeres

  Sarcolemma ↔️ Transmits nerve impulses

  Sarcoplasmic Reticulum ↔️ Stores calcium ions
• What ion is stored and released by the sarcoplasmic reticulum?

  Calcium
• T-tubules are inward extensions of the sarcolemma
• Order the following components of skeletal muscle from largest to smallest:

  1️⃣ Muscle Fibre

  2️⃣ Myofibril

  3️⃣ Sarcomere
• Myofibrils are long, cylindrical contractile units within muscle fibres.
• What is the role of muscle fibres in skeletal muscle?

  Produce movement
• Match the structure with its function in muscle fibers:

  Myofibrils ↔️ Contract to shorten muscle fiber

  Sarcomeres ↔️ Basic contractile units

  Sarcoplasmic Reticulum ↔️ Stores calcium ions

  T-tubules ↔️ Transmit action potentials
• Actin filaments are thin filaments that slide along myosin
• The sliding filament theory explains how muscle contraction occurs.
• What type of muscles are skeletal muscles?

  Voluntary
• Order the hierarchical organization of skeletal muscle from smallest to largest:

  1️⃣ Muscle Fibre

  2️⃣ Fascicle

  3️⃣ Muscle
• What does a fascicle consist of in skeletal muscle?

  Bundle of muscle fibres
• What is the primary function of muscle fibres in skeletal muscle?

  Produce movement
• Myofibrils are long, cylindrical contractile units that contain sarcomeres
• Sarcomeres contain actin and myosin filaments that cause muscle contraction.
• What is the sarcolemma and its role in muscle fibres?

  Plasma membrane, transmits impulses
• The sarcoplasmic reticulum stores and releases calcium ions.
• T-tubules are inward extensions of the sarcolemma that facilitate rapid transmission of action potentials.
• Match the component with its description:

  Muscle Fibres ↔️ Single muscle cells with multiple nuclei

  Myofibrils ↔️ Long, cylindrical contractile units

  Sarcomeres ↔️ Repeating segments with actin and myosin

  Sarcolemma ↔️ Plasma membrane surrounding muscle fibres
• Arrange the components of skeletal muscle from largest to smallest:

  1️⃣ Muscle Fibres

  2️⃣ Myofibrils

  3️⃣ Sarcomeres