It is made up of two layers, each made up of a lipid bilayer. lipid bilayer is enveloped with holes, called nuclear pores, to regulate the exchange of substances (for example, proteins and RNA) between the nucleus and the cytoplasm. Perinuclear space is space between membranes. The outer membrane is contiguous with the endoplasmic reticulum. The inner membrane is constituted by a network of filaments called nuclear lamina, The lamina attach to chromosomes. It also acts like a shield for the nucleus.