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.
But even standard loveseats come in a variety of sizes to fit every home, including: 1  Compact twin-size loveseats. 2  Small standard loveseats that measure 52 inches long arm to arm. 3  Medium loveseats are slightly larger that the small at 58 inches long. 4  Full loveseats can be as long as 64 inches from arm to arm.