Depolarization



- Discussion: Stimulus for Contraction:
    - stimulus for muscle contraction is an electrical impulse from motor nerve at the motor end-plate or neuromuscular junction;
    - when sarcolemma is stimulated by an incoming impulse, sodium, potassium, and chloride ions move about w/in transverse tubules 
         to spread impulse and depolarize membranes;
        - this depolarization in turn causes a release calcium ions into sarcoplasm;
        - this in turn, causes all filaments in a muscle fiber contract together



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, December 5, 2011 10:26 am