12-21. THE GENERAL REFLEX ARC
The pathway followed by the stimulus (impulse) from beginning to end is the
reflex arc. The general reflex arc (Figure 12-10) of the human nervous system has a
minimum of five components:
Figure 12-10. The general reflex arc.
a. The stimulus is received by a receptor organ specific to that stimulus.
b. From the receptor organ, the stimulus is carried to the CNS by way of an
afferent (sensory) neuron within the appropriate peripheral nerve. The cell body of this
afferent neuron is located in the posterior root ganglion of a spinal nerve or the
individual ganglion of a cranial nerve.
c. Within the spinal cord or brainstem, the terminal of the afferent neuron
synapses with the interneuron, or internuncial neuron.
INTER = between
NUNCIA = messenger