FIGURE 2.

Transverse tubules (TTs) and other related structures in the sarcomere. (A) The TT, schematic diagram of the TT, ryanodine receptor (RyR) cluster, and junctional sarcoplasmic reticulum (jSR). (B) The intermyofibrillar mitochondrion. Relationship between TT structures and the intermyo-fibrillar mitochondrion. (C) The reticular longitudinal sarcoplasmic reticulum (SR). The longitudinal SR wraps around the mitochondrion and is linked to the jSR through diffusion-restricted connections [in color in Annals Online].