【正文】
nt model Muscle shortening is due to movement of the actin filament over the myosin filament Reduces the distance between Zlines Changes in the appearance of a Sarere during the Contraction of a Skeletal Muscle Fiber 按任意鍵 飛入橫橋擺動動畫 肌節(jié)縮短 =肌細(xì)胞收縮 橫橋擺動 橫橋與結(jié)合位點結(jié)合,分解 ATP釋放能量 Ca2+與肌鈣蛋白結(jié)合 肌鈣蛋白的構(gòu)型 終池膜上的鈣通道開放 終池內(nèi)的 Ca2+進入肌漿 肌絲滑行的過程 原肌球蛋白位移,暴露細(xì)肌絲上的結(jié)合位點 Sara shorten Cross bridge pivoting Cross bridge bind to actin,and hydrolysis of ATP provides energy Ca2+binds to troponin Ca2+ channel open Ca2+released from cisternae into sarcoplasm 肌絲滑行的過程 (video) Tropomyosin moves and exposing myosin binding site on actin 肌絲滑行幾點說明 : 1) 肌細(xì)胞收縮時肌原纖維的縮短 ,并不是肌絲本身縮短 ,而是細(xì)肌絲向肌節(jié)中央 (粗肌絲內(nèi) )滑行 。 3) 橫橋的循環(huán)擺動在肌肉中是非同步的 , 從而肌肉產(chǎn)生恒定的張力和連續(xù)的縮