At these points, called synapses, electrical impulses are transduced into chemical signals, which are received at membranes of other nerves or muscles. Dendrites can be found directly on perikarya or at ends of axons. We consider three kinds of neurons. The upper drawing shows a monopolar neuron, which have a single projection from parakarya. This single projection branches so that there is a dendrite at one end and terminal aborization at the other.
Most insect neurons are monopolar.
This arrangement is suited for direct transmission of environmental stimuli to the central nervous system. Information from outside of an insect, such as light or mechanical stimulus, is most likely conducted from peripheral sense cells directly to central nervous system ganglia by axons without synaptic interruptions. These axons are called afferent axons. Most afferent neurons synapse with other neurons that in turn synapse with still other neurons or else with efferent neurons. The neurons that form connections between afferent and efferent neurons are called interneurones.