Nerve cell. Computer artwork of a nerve cell or neuron. Other nerve cells are seen in the background. Neurons are responsible for passing information around the central nervous system (CNS) and from the CNS to the rest of the body. Each nerve cell comprises a body (circular) surrounded by numerous extensions called dendrites. Dendrites collect information from other nerve cells or from sensory cells. Each neuron also has one process called an axon, which passes information to other nerve cells, or to effector cells such as muscle fibres. This neuron's axon is covered with a myelin sheath (blue), an insulating fatty layer that increases the speed at which nerve impulses travel.