Studies upon Secretory Activity of Glands of the Oral and Pharyngeal Mucous Membranes.

Abstract

These studies were undertaken to extend our very limited knowledge relating to the secretory activity of the small mucous and serous glands of the oral and pharyngeal mucous membranes. I have been unable to discover any adequate description of the nerve, supply to the various groups of these glands. Therefore, to confirm and to amplify the fragmentary reports of previous workers I determined what nerves carry such secretory fibers by directly stimulating the nerve trunks in 12 anesthetized dogs. I found the innervation to be a dual one through both the sympathetic and cranial autonomic systems, as has been described. Stimulation of the cervical sympathetic trunk in the neck caused secretion homolaterally over all of the gland bearing areas of the oral and pharyngeal mucous membranes. The maxillary division of the fifth cranial nerve sends a branch to the orbital gland, and through its spleno-palatine branches supplies the glands of the hard palate, the soft palate, the tonsils, the pillars of the fauces, and the nasopharynx. Of the mandibular division of the fifth cranial nerve, the buccinator branch innervates the orbital gland and the glands of the cheek and lower lip. The lingual branch supplies the glands of the floor of the mouth. Secretory fibers from the glossopharyngeal nerve reach the glands at the base of the tongue and the posterior fourth of the side of the tongue, the hard and soft palates, the tonsil, the pillars of the fauces, and the nasopharynx. The vagus sends fibers to the nasopharyngeal and epiglottic glands, and to the glands at the base of the tongue over a small area near the middle line. I believe these small glands do not secrete continuously, but only reflexly in response to an adequate stimulus as is the case for the salivary glands. Studies upon 5 intact, unanesthetized dogs and 4 human subjects have shown that the glands of easily observed areas, namely, the dog's lower lip and cheek and the human lips and palate, are reflexly excited by a large number of different stimuli, among which are pressure upon the tongue or palate, licking and swallowing movements, the odors of acetic acid, ammonia, and ether, and the taste of salt, sugar, hydrochloric and acetic acids, and magnesium sulphate.