GENERAL HISTOLOGY

Detailed explanation-1: -Each myofibril is surrounded by the sarcoplasmic reticulum, which is closely associated with the transverse tubules. The sarcoplasmic reticulum acts as a sink of Ca+ ions, which are released upon signalling from the transverse tubules.

Detailed explanation-2: -The sarcoplasmic reticulum is a complex network of specialized smooth endoplasmic reticulum that is important in transmitting the electrical impulse as well as in the storage of calcium ions. These longitudinal tubules form a membrane-bound system of tubules and cisterns that surround the myocytes.

Detailed explanation-3: -Skeletal muscle fibers are multinucleated cells that contain mostly myofibrils suspended in an aqueous media termed the sarcoplasm.