Retrieving "Z Disks" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Sarcoplasmic Reticulum

   Linked via "Z-disks"

   Longitudinal Tubules
   The longitudinal tubules constitute the main body of the $\text{SR}$ network. These tubules run parallel to the myofibrils, spanning the distance between adjacent Z-disks. Their membranes are densely packed with the Sarco/Endoplasmic Reticulum $\text{Ca}^{2+}$-ATPase ($\text{SERCA}$), the primary pump responsible for actively transporting $\text{Ca}^{2+}$ back into the lumen against a steep electrochemical gradient following [muscle relaxation](/entries/muscle-relaxat…