In vertebrates it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinalcord. The PNS consists mainly of nerves, which are enclosedbundlesof the long fibers or axons, that connect the CNS to every other part of the body.

The cerebellum receives information from thesensorysystems, the spinal cord, and other parts of the brain and then regulatesmotormovements. The cerebellum coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth and balanced muscular activity.

Sensoryneurons carry signals from the outer parts of your body (periphery) into the centralnervoussystem.Motorneurons (motoneurons) carry signals from the centralnervoussystem to the outer parts (muscles, skin, glands) of your body. Interneurons connect various neurons within the brain and spinal cord.

Thenervous systemuses electrical and chemical means to help all parts of the body to communicate with each other. The brain and spinal cord make up the centralnervous system.Nerveseverywhere else in the body are part of the peripheralnervous system.