Endoplasmic Reticulum

**Semantic type:** Cell Component

**Definition:** The endoplasmic reticulum is a network of tubular membranes within the cytoplasm of the cell, occurring either with a smooth surface (smooth endoplasmic reticulum) or studded with ribosomes (rough endoplasmic reticulum), involved in the transport of materials. (Infoplease Dictionary)

**Synonyms:** - ER