Neurones are nerve cells that carry information as tiny electrical signals. There are three different types of neurones, each with a slightly different function: sensory neurones carry signals from receptors to the spinal cord and brain relay neurones carry messages from one part of the CNS to another motor neurones carry signals from the CNS to effectors. A neurone has a 'head' at one end where the nucleus, cytoplasm, cell membrane and dendrite are. The axon is tail-like, with nerve endings at the end which look like branches.