Erayga " saxan dhamaadka mootada" caadi ahaan waxa loola jeedaa qaab dhismeed gaar ah oo laga helay isgoysyada neuromuscular (NMJ) ee laf dhabarta. Waa gobol uu matoorka neuron-ku ku xidho fiber muruqa lafaha ah Waxaa lagu gartaa cufnaanta sare ee reseptors acetylcholine ee xuubka muruqa, kaas oo u oggolaanaya gudbinta dareenka dareenka muruqa. Marka dareenka neerfaha uu gaaro saxanka dhamaadka mootada, waxay kicisaa sii deynta acetylcholine, neurotransmitter, oo gala dillaaca synaptik. Acetylcholine ka dib waxay ku xidhaa reseptors on saxan dhamaadka motor, taasoo keentay in depolarization ee fiber muruqa iyo murqaha ku xiga. murqaha lafaha, oo awood u siinaya xakamaynta muruqa ikhtiyaariga ah iyo dhaqdhaqaaqa.