Figure 4-9A cross-sectional view of a typical cell nucleus
The nuclear envelope consists of two membranes, the outer one being continuous with the endoplasmic reticulum membrane (see also Figure 12-9). The space inside the endoplasmic reticulum (the ER lumen) is colored yellow; it is continuous with the space between the two nuclear membranes. The lipidbilayers of the inner and outer nuclear membranes are connected at each nuclear pore. Two networks of intermediate filaments (green) provide mechanical support for the nuclear envelope; the intermediate filaments inside the nucleus form a special supporting structure called the nuclear lamina.