Nuclear pores are tiny openings in the nuclear envelope, which surrounds the nucleus of a cell. These pores are made up of proteins and allow the transport of molecules between the nucleus and the cytoplasm. They play a crucial role in regulating the movement of substances like RNA and proteins, ensuring that essential materials can enter and exit the nucleus as needed. Each nuclear pore complex is composed of multiple proteins called nucleoporins. These structures form a selective barrier, permitting the passage of small molecules freely while controlling the entry of larger molecules. This selective transport is vital for maintaining the cell's functions and overall health.