According to the National Institute of Health, or NIH, the nuclear membrane is made up of two separate membranes, a nuclear lamina and nuclear pore complexes. Another common term for the nuclear membrane is the nuclear envelope, or NE, because it envelopes the contents of the cell's nucleus.
The parts of the nuclear envelope all have separate functions and work together to protect the nucleus, as described by the NIH and the British Society for Cell Biology:
- Nuclear membranes - These two membranes act as barriers, and prevent the passage of molecules between the nucleus and the cytoplasm. The membranes also help to maintain the nucleus as a separate area of the cell.
- Nuclear lamina - These are filaments that give structure and support to the nuclear membranes. The lamina are found between the two nuclear membranes. That space is known as the perinuclear space.
- Nuclear pore complexes - Nuclear pores are small holes that enable material to move out of and into the nucleus.
The NIH states that one of the most important functions of the NE is to keep the contents of the nucleus separate from the rest of the cell. It is especially important to keep the DNA separate from the chemical reactions that take place in the cytoplasm of the cell. As the cell undergoes replication, the parts of the NE dissolve then reform once the process is complete.