A neuron has a cell body with a nucleus, from which a number of extensions arise. Called dendrites, their function is to carry information from their surroundings towards the cell body, where it is transferred to the axon, and onwards to the axon terminal. Information is passed across the synapse via electrical or chemical impulses (neurotransmitters), sending a similar reaction off in the next neuron.
Axons are often enclosed in myselin sheath (which insulates and facilitates rapid transmission). The myelin sheath are formed by schwann cells, and the junction or space between these segments is called the node of ranvier.