The membranes of the endoplasmic reticulum are continuous with the outer nuclear membrane.

Concept: A type of organelle found in eukaryotic cells is the endoplasmic reticulum that forms an interconnected network of flattened, membrane-enclosed sacs or tube-like structures known as cisternae. 

The membranes of the endoplasmic reticulum are continuous with the outer nuclear membrane. ER has two types they are rough endoplasmic reticulum and smooth endoplasmic reticulum. The main function of rough ER is to produce proteins in the cells and ribosomes are attached to their surface. The main function of smooth ER is to produce lipids and also detoxify toxins in the body in the kidney and liver.