Endoplasmic reticulum
ID: endoplasmic-reticulum
The endoplasmic reticulum is a membrane-enclosed network of tubules and flattened sacs in a typical eukaryotic biological cell. Its continuous boundary encloses the ER lumen, separate from the cytosol, and connects with the outer nuclear envelope. Rough endoplasmic reticulum and smooth endoplasmic reticulum are regions of this network.[ref]
The Endoplasmic Reticulum. The Cell: A Molecular Approach, 2nd edition by Geoffrey M. Cooper; The Endoplasmic Reticulum, opening paragraph and Figure 9.1: continuous membrane and nuclear-envelope connection
One endoplasmic reticulum network with rough and smooth regions
. Original conceptual cross-section: blue interiors connect, while attached ribosomes distinguish rough regions. Shapes and dimensions are illustrative, not measured fluorescence or electron microscopy. Details.
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