Results : after cryofixation , basement membranes of skeletal muscle consisted of only one electron dense layer , t tubules were round , core cylinders were observed in terminal cisternae and there were thread - like protein particles on the membranes of terminal cisternae 化學(xué)固定后,縫匠肌基膜由兩層組成:一層電子密度低,另一層電子密度高;橫小管為扁平狀或啞鈴狀;終池內(nèi)僅有一些散在的電子密度高的顆粒,終池膜上有幾個腳狀突起伸向橫小管。
Terminal cisternae are enlarged areas of the sarcoplasmic reticulum surrounding the transverse tubules. These discrete regions within the muscle cell store calcium (increasing the capacity of the sarcoplasmic reticulum to release calcium) and release it when an action potential courses down the transverse tubules, eliciting muscle contraction.