Transverse tubules. - tubules formed by invaginations of the sarcolemma and flanked by the sarcoplasmic reticulum, they carry action potentials deep into the muscle fiber. T tubules and SR provide tightly linked signals for muscle contraction. T tubules at each A band/I band junction-continuous with the sarcolemma.
Standard Sizes of Sofas. Sofas vary in size, from 6 to 8 feet long and 32 to 40 inches deep for a standard size sofa, to 4 to 6 feet long and 28 to 30 inches deep for a loveseat.The actual depth of the seating area is reduced by the depth of the sofa's arms and back of the sofa.ofas vary in size, from 6 to 8 feet long and 32 to 40 inches deep for a standard size sofa, to 4 to 6 feet long and 28 to 30 inches deep for a loveseat.
railroad ties. The usual lengths are 8, 8Â½, or 9 feet, with a cross section between 6 inches Ã 7 inches and 7 inches Ã 9 inches. Ties treated with preservative, as all are today, can last an average of 25 to 40 years, although they may have a much shorter life due to mechanical wear.