E109 lecture muscle cells the other electrically excitable cell muscle cells (muscle fibers) also generate action potentials. Steps for action potential are the same in a neuron action potential: action potential from cns happens first (neuron action potential, muscle action potential happens second muscles tend to have a pull. =skeletal muscles are usually in antagonist pairs (flexion vs. extension) Start with skeletal muscles muscle fiber =single muscle cell muscle fibers bound together in a muscle fascicle (bundle of muscle fibers) nerves will be both afferent (bring in sensory info) and efferent. Sarcolemma =cell membrane of muscle cell; sarco is common prefix for muscle cell components. Sarcoplasmic reticulum: endoplasmic reticulum voltage propagated along the cell membrane. Force generate in the myofibrils (thick and thin filaments) Arrangement of myofibrils inside muscle fiber make the muscle appear striated . Don"t memorize a band, z disk, but should know sacromere : 1 complete unit. Sacromere from first z disk to second z disk.