Word Origin and History for philo- Expand. before vowels phil-, word-forming element meaning loving, fond of, tending to, from Greek philo-, comb. form of philos dear (adj.), friend (n.), from philein to love, of unknown origin. Productive of a great many compounds in ancient Greek.
One way to classify neurons is by the number of extensions that extend from the neuron's cell body (soma). Bipolar neurons have two processes extending from the cell body (examples: retinal cells, olfactory epithelium cells).
Bipolar neurons are relatively rare. They are sensory neurons found in olfactory epithelium, the retina of the eye, and ganglia of the vestibulocochlear nerve. Multipolar neurons are the most common type of neuron. They are located in the central nervous system (brain and spinal cord) and in autonomic ganglia.