Neurons are the core elements of the nervous system. They receive, integrate, and transmit information through electrical impulses and communicate with other neurons via chemical signals. The three main components of a neuron are the cell body, which contains the nucleus, dendrites that receive messages and transmit them to the cell body, and the axon, which transmits messages to other neurons. Additional components include a myelin sheath made of Schwann cells that surrounds axons and dendrites, and the neurilemma, a cytoplasmic layer that allows regeneration of damaged nerves.