Neural Organization of Swallowing and Related Disorders.

DOI 2 Citations 37 References

Bibliographic Information

Other Title
  • 神経機序からみたえん下とその病態

Search this article

Abstract

New findings of morphological and physiological investigations into neural control of swallowing and swallowing disorders are described.<BR>In cats and humans, free nerve endings and taste buds were observed in the laryngeal epithelium, and beaded nerve terminals forming a network were found in the subepithelium. These findings suggest that free nerve endings easily respond to mechanical and chemical stimulation.<BR>Based on physiological investigations, we propose the existence of highly sensitive mechanoreceptors known as“chemoreceptors”. It is thought that the structures and characteristics of these receptors are appropriate for elicitation of the protective reflex and the swallowing act.<BR>Brainstem projections of the sensory fibers in the glossopharyngeal nerve and superior laryngeal nerve (SLN) were studied. The results suggest that the majority of sensory impulses from the pharyngolaryngeal region are carried into the interstitial subnucleus of the nucleus tractus solitarius (NTS) through the glossopharyngeal nerve and the SLN.<BR>The movements of the pharynx and larynx during the second (pharyngeal) stage of reflexogenic swallowing are highly reproducible. This circumstance suggests that the movements are not a sequence of reflexes but are controlled by output from the central pattern generator (CPG) for swallowing. The location in the medulla oblongata and characteristics of the swallowing-related neurons (SRN), which receive orthodromic input from the SLN and burst during swallowing, were studied in the cat. The SRNs were classified into three types. Type I is a sensory-relay neuron which exists in the NTS and relays input from the SLN. Type II is an interneuron which exists in the parvocellular reticular formation and receives oligosynaptic input from the SLN. Type III is a motoneur-on which drives the swallowing-related muscles in the pharyngolaryngeal region.<BR>Clarification of pathophysiology in patients with dysphagia is necessary for appropriate treatment. From the results of the clinical investigation, dysphagia caused by disorders of the central nervous system divided into dysphagia caused by lesion of the corticobulbar tract and dysphagia caused by lesion of the brainstem involving the CPG. Pathophysiology and treatment are different for each group.

Journal

Citations (2)*help

See more

References(37)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top