So what exactly is a sensory neuron? A sensory neuron is basically the neuron that begins at some receptor. It receives a signal from the environment and then it sends that signal into the central nervous system. So sensory neurons are neurons that receive electrical signals from receptors and carry those to other neurons or to the central nervous system. Now, sensory neurons are also known as aphary neurons. So notice that we have an E here and we have an A here.