THE MYOFILAMENT ARRANGEMENT IN THE FEMORAL MUSCLE OF THE COCKROACH, LEUCOPHAEA MADERAE FABRICIUS

摘要: The structure of the femoral muscle cockroach, Leucophaea maderae, was investigated by light and electron microscopy. several hundred fibers either extensor or flexor are 20 to 40 µ in diameter transverse sections subdivided into closely packed myofibrils. In glutaraldehyde-fixed epoxy resin-embedded material stretched fibers, A band is about 4.5 long, thin filaments 2.3 length, H zone I vary with amount stretch, M absent. reveal area a single overlap thick an array 10 12 encircling each filament; whereas, double which interdigitate from opposite ends band, show twofold increase number. filament approximately 205 185 along most its but at 0.2 end it tapers point. Furthermore, some well oriented, very these have electron-transparent cores. 70 A. Transverse exhibit sarcolemma invaginating clearly regular intervals lateral regions band. Three distinct types mitochondria associated muscle: oval, elongate, type three processes. It evident, this muscle, that sliding hypothesis valid, perhaps function extra tensile strength fiber create additional reactive sites between filaments. These probably required for functioning long sarcomeres.