Muscle Fibers, Fast-Twitch

MeSH ID: D018656

DEFINITION: Skeletal muscle fibers having high myofibrillar ATPase activity, high glycolytic enzyme activities, and an intermediate glycogen content which produce a fast twitch. There are two types. Fast fatigable fibers, also called white fibers, have a low myoglobin content, and a small mitochondrial content, and fatigue rapidly due to their limited glycogen content and low capacity for oxidative metabolism. Fast fatigue-resistant fibers, also called red fibers, have a large mitochondrial content and a high myoglobin content, related to their resistance to fatigue. (From Best, Physiological Basis of Medical Practice, 12th ed, p100)

Related Concepts:

• Muscle Fibers, Fast-Twitch [M0027953]
  Concept Semantic Types:
  • Cell [T025]
  Concept Terms:
  • Muscle Fibers, Fast Twitch [T055534]
  • Muscle Fibers, Type II [T055535]
• Muscle Fibers, White [M0027955]
  Concept Semantic Types:
  • Cell [T025]
  Concept Terms:
  • White Muscle Fibers [T055537]
• Muscle Fibers, Red [M0027954]
  Concept Semantic Types:
  • Cell [T025]
  Concept Terms:
  • Red Muscle Fibers [T055536]

Qualifiers:

chemistry [Q000737] ; classification [Q000145] ; cytology [Q000166] ; drug effects [Q000187] ; enzymology [Q000201] ; immunology [Q000276] ; metabolism [Q000378] ; microbiology [Q000382] ; parasitology [Q000469] ; pathology [Q000473] ; physiology [Q000502] ; radiation effects [Q000528] ; radiography [Q000530] ; radionuclide imaging [Q000531] ; secretion [Q000557] ; transplantation [Q000637] ; ultrasonography [Q000736] ; ultrastructure [Q000648] ; virology [Q000821]

Tree Structure:

• Anatomy [A ]
  • Musculoskeletal System [A02 , D009141]
    • Muscles [A02.633 , D009132]
      • Muscle Fibers [A02.633.565 , D018485]
        • Muscle Fibers, Fast-Twitch [A02.633.565.600, D018656]

• Anatomy [A ]
  • Cells [A11 , D002477]
    • Muscle Cells [A11.620 , D032342]
      • Muscle Fibers [A11.620.249 , D018485]
        • Muscle Fibers, Fast-Twitch [A11.620.249.400, D018656]