Sympathetic innervation of human parotid and submandibular glands

Background: The parotid and submandibular glands are two of the three major salivary glands. Although the postganglionic sympathetic fibers are known to be from the superior cervical ganglion, the distribution of the sympathetic fibers in these glands still needs additional study. Materials and methods: Postoperative specimens from human parotid and submandibular glands were used. The glyoxylic catecholaminergic histofluorescence method was employed on the tissues to study the sympathetic innervation. One percent neutral red was used as a counterstain. Results: Most sympathetic fibers were found around the glandular area and adventitial layers of vessels, and a few were found in the capsule or interglandular connective tissues. The ducts lacked sympathetic innervation. Conclusion: Sympathetic innervation may have a direct control on the glandular secretions of these two major salivary glands. Because the secretory ducts lack sympathetic innervation, the sympathetic nerves may not directly affect the ducts.