(2) Sensory neuron. This neuron conducts the impulse from the receptor to
its axonal end in the central nervous system.
(3) Center. This is a receiving area (usually in the central nervous system)
in which the incoming sensory impulse connects with an
outgoing motor impulse. The impulse may be repressed, transmitted, or rerouted in the
(4) Motor neuron. The job of the motor neuron is to transmit the impulse to
the proper body organ.
(5) Effector. The effector is the organ of the body that responds to the
impulse from a motor neuron. An effector may be either a muscle or a gland.
Figure 1-4. The pathway of an impulse over the reflex arc.