The pons is a broad, horseshoe shaped portion of the brain (often termed the brain stem) located in the upper segment of the region that gradually transitions into the spinal cord. Consisting of large bundles of nerve fibers, the pons connects the two halves of the cerebellum (the portion of the brain that coordinates movements of voluntary or skeletal muscles) and is vital in coordinating movements involving the right and left sides of the body. The pons serves as a relay station that links the more primitive parts that operate automatically such as the medulla oblongata and the cerebellum with the higher regions of the brain such as the cerebrum. The structure, formally referred to as pons varolii, is named after its discoverer the Italian anatomist C. Varoli and is derived from the Latin word pons meaning "bridge".