Organization of Skeletal Muscle Flashcards

Organization of Skeletal Muscle

• Sarcomere: Basic unit of striated muscle, essential for muscle contraction, comprising repeating contractile units.
• Epimysium: Layer of collagenous connective tissue enveloping the entire muscle, providing structural support and separating it from surrounding tissues.
• Perimysium: Connective tissue sheath surrounding muscle fiber bundles (fascicles), facilitating blood flow and nerve distribution.
• Endomysium: Connective tissue that extends from the perimysium, encasing individual muscle fibers, aiding nutrition and signaling.
• Myofibril: Elongated contractile threads within striated muscle cells, composed of repeating sarcomeres responsible for muscle contraction.
• Striations: Characteristic bands in skeletal muscle tissue resulting from the arrangement of myofibrils and sarcomeres, indicating the presence of contractile proteins.
• Sarcolemma: Cell membrane of muscle fibers, essential for action potential propagation and maintaining the internal environment of the muscle cell.
• Transverse Tubule: Invaginations of the sarcolemma that penetrate deep into the muscle fiber, facilitating the spread of electrical impulses and ensuring synchronous contraction.
• Sarcoplasmic Reticulum: Specialized form of smooth endoplasmic reticulum in striated muscle cells that regulates calcium ion levels, crucial for muscle contraction and relaxation.
• Actin: Protein that forms thin filaments in muscle contraction; interacts with myosin to facilitate movement.
• Myosin: Protein forming thick filaments, playing a key role in muscle contraction by binding to actin filaments and pulling them together.
• Fascicle: Groups of muscle fibers, organized to enhance muscle function, with multiple fascicles comprising a single muscle.