Muscle Physiology
Lecture: Muscle Physiology I. Anatomy of Skeletal Muscle CELL (Muscle Fiber) A. General Features 1. multinucleated cells (syncytium: from fusion) 2. sarcolemma - special name for plasma membrane 3. very long compared to other cells (1 - 300 mm) 4. not unusually wide diameter (10 - 100 microns) 5. sarcoplasm - rich in glycogen and myoglobin 6. myoglobin - stores oxygen; similar to hemoglobin 7. special structures: myofibrils and sarcoplasmic reticulum B. Ultrastructure of Myofibrils ¼ 1. muscle cell contains many parallel myofibrils 2. myofibrils have DARK bands (A bands) and LIGHT bands (I bands) that cause "striated" a...