Arm-like extensions that begin at the bulge of the Milky Way are called spiral arms. They are named as the Perseus Arm, the Scutum-Crux Arm, the Carina and Sagittarius arm, and the Norma and Cygnus Arm. It has been discovered that there is an outer extension to the Cygnus Arm. The Orion Arm, which is a relatively smaller arm, houses our solar system.