In the present study, injections of the anterior chamber were used to label the postganglionic and preganglionic afferents to the iris sphincter pupillae muscle.
This extent of transsynaptic labeling was not obviously correlated with the amount of direct retrograde labeling of postganglionic neurons in the ipsilateral ciliary ganglion.
These biological responses are mediated both by direct autonomic innervation of target organs by postganglionic neurons and by secretion of epinephrine and norepinephrine by the adrenal medulla.
The two exceptions mentioned above are postganglionic neurons of sweat glands and chromaffin cells of the adrenal medulla.
The "sympathetic postganglionic fibers" originate from the superior cervical ganglion.
There, they synapse with postganglionic fibers which reach the gland by hitch-hiking via the auriculotemporal nerve, a branch of the mandibular nerve.
Once inside the prevertebral ganglia, the individual neurons comprising the nerve synapse with their postganglionic neuron.
Here the fibers synapse and postganglionic fibers join the fibers of the maxillary nerve, which travels through the inferior orbital fissure.
