title: Junctional feet and particles in the triads of a fast-twitch muscle fibre.
abstract: Structural details of junctional feet in triads of fish muscle are described. These feet have a less dense central core and contact both sarcoplasmic reticulum and T-tubule membranes at tetragonally disposed sites. The distribution of intramembraneous particles differs at the junctional T-membrane, and the junction is asymmetric.
mesh_terms: D000400:Air Sacs; D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D005399:Fishes / Q000033:anatomy & histology*; D007425:Intracellular Membranes / Q000648:ultrastructure; D008854:Microscopy, Electron; D008954:Models, Biological; D009119:Muscle Contraction; D009132:Muscles / Q000648:ultrastructure*; D009210:Myofibrils / Q000648:ultrastructure; D012519:Sarcoplasmic Reticulum / Q000648:ultrastructure*