|
KMID : 0376219830200020237
|
|
Chonnam Medical Journal
1983 Volume.20 No. 2 p.237 ~ p.245
|
|
|
Inhibitory Mechanism of the Cervical Sympathetics on the Submaxillary Salivation in the Cat
|
|
|
|
|
Abstract
|
|
|
Since the time of Ludwig and Heidenhain the cervical sympathetic trunk has been assumed to carry specific serectory fibers for the submaxillary gland. But the response of the submaxillary gland to the cervical sympathetic stimulation is very small and short-lasting or completely lacking in exceptional cases; it diminishes quickly and often ceases wholly in spite of continued stimulation of the cervical sympathetic. Thus, the hypothesis has been doubted that there are serectory fibers in the sympathetic trunk. The scanty flow of saliva observed on the stimulation of the sympathetic trunk may be due to excitation of motor fibers innervating contractile elements in the gland which expel saliva already present in the ducts. Alternatively, a flow of saliva seen during stimulation of the sympathetic nerve may be caused by "Sympathies" diffusing from the vasoconstrictor nerve terminals to the serectory cells. On the other hand, the fact that a flow of saliva induced by parasympathetic stimulation is diminished by the superimposed sympathetic stimulation has led to the suggestion that the sympathetic trunk carries inhibitory serectory fibers to the gland.
Recently, the inhibitory effects of the cervical sympathetic on the reflex submaxillary salivation and on the submaxillary blood flow were reported. However, the inhibitory mechanism of the sympathetic was not fully elucidated. It has been suggested that blood flow to the salivary gland is closely related to the salivary secretion. In this study, effects of stimulation of the cervical sympathetic on the submaxillary salivation and blood flow were analyzed to clarify the role of the sympathetic innervation to the submaxillary gland.
Stimulation of the central end of the pharyngeal branch of the vagus or that of the lingual nerve elicited both copious submaxillary salivation and increase in the blood flow, and the responses were decreased markedly by the superimposed stimulation of the cervical sympathetic. The responses of the submaxillary salivation and increased blood flow to the stimulation of central end of the lingual nerve were diminished by the legation of the common carotid artery. Copious submaxillary salivation and increased blood flow induced by the chorda stimulation or by the intravenous infusion of pilocarpine were also decreased by the stimulation of the cervical sympathetic.
However, in all of the observations made in this study, it was clearly noted that the decreased submaxillary blood flow always preceded the decrease in salivary flow on stimulation of the sympathetics and that the decreased blood flow recovered prior to the salivary flow upon cessation of the sympathetic stimulation.
These results indicate that the inhibitory effect of the cervical sympathetic on the submaxillary salivation is caused by decreasing the blood flow to the gland, which is evoked by the excitation of the sympathetic vaso-constrictor fibers.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|