7.1.1 Structure of Skeletal Muscle

• Skeletal muscles are voluntary muscles that attach to bones
• Skeletal muscles contract under conscious control.
• Arrange the hierarchical levels of skeletal muscle from smallest to largest.

  1️⃣ Muscle Fibre

  2️⃣ Fascicle

  3️⃣ Muscle
• A muscle fibre contains myofibrils
• Match the skeletal muscle level with its description.

  Muscle Fibre ↔️ Single muscle cell

  Fascicle ↔️ Bundle of muscle fibres

  Muscle ↔️ Group of fascicles
• Each hierarchical level of skeletal muscle contributes to muscle contraction.
• The plasma membrane of a muscle fibre is called the sarcolemma
• Muscle fibres are single cells with multiple nuclei.
• What is the role of sarcomeres in muscle fibres?

  Cause muscle contraction
• The sarcoplasmic reticulum stores and releases calcium ions.
• What is the function of T-tubules in skeletal muscle?

  Transmit action potentials
• Muscle fibres contain myofibrils for contraction.
• Arrange the hierarchical levels of skeletal muscle from smallest to largest.

  1️⃣ Muscle Fibre

  2️⃣ Fascicle

  3️⃣ Muscle
• Skeletal muscles are voluntary muscles that attach to bones
• What is the primary role of myofibrils in muscle contraction?

  Contain sarcomeres
• Sarcomeres contain both actin and myosin filaments.
• Myofibrils are long, cylindrical contractile units
• What is the function of muscle fibres in skeletal muscle?

  Contract to produce movement
• Match the component of skeletal muscle with its role.

  Sarcomere ↔️ Causes muscle contraction

  Sarcoplasmic Reticulum ↔️ Stores calcium ions

  T-Tubules ↔️ Transmit action potentials
• What are muscle fibres defined as?

  Single muscle cells
• Myofibrils contain sarcomeres, which are essential for muscle contraction.
• Which filaments are contained within sarcomeres?

  Actin and myosin
• Components of skeletal muscle include muscle fibres, myofibrils, and sarcomeres
• Match the component of skeletal muscle with its role:

  Muscle Fibres ↔️ Contract to produce movement

  Myofibrils ↔️ Contain sarcomeres

  Sarcomeres ↔️ Cause muscle contraction
• What is the role of the sarcolemma in muscle fibres?

  Transmits nerve impulses
• The sarcoplasmic reticulum stores and releases calcium ions for muscle contraction.
• T-tubules are inward extensions of the sarcolemma
• Which part of the skeletal muscle facilitates rapid transmission of action potentials?

  T-tubules
• All components of skeletal muscle work together to enable muscle contraction and movement.
• What are myofibrils composed of?

  Actin and myosin filaments
• Actin filaments form binding sites for myosin
• Skeletal muscles are voluntary muscles controlled by conscious effort.
• What is a fascicle in skeletal muscle?

  Bundle of muscle fibres
• Single muscle cells with multiple nuclei are called fibres
• Myofibrils are contractile units that contain sarcomeres.
• Match the skeletal muscle component with its description:

  Sarcomere ↔️ Contains actin and myosin filaments

  Sarcolemma ↔️ Plasma membrane surrounding muscle fibres

  Sarcoplasmic Reticulum ↔️ Stores and releases calcium ions
• The sarcoplasmic reticulum stores and releases calcium
• T-tubules are inward extensions of the sarcolemma that facilitate action potential transmission.
• Order the following skeletal muscle components from largest to smallest:

  1️⃣ Muscle Fibres

  2️⃣ Myofibrils

  3️⃣ Sarcomeres
• Match the skeletal muscle component with its role:

  Muscle Fibres ↔️ Contract to produce movement

  Myofibrils ↔️ Contain sarcomeres

  Sarcolemma ↔️ Transmits nerve impulses