Brain Neurorehabil.  2009 Sep;2(2):98-102. 10.12786/bn.2009.2.2.98.

Normal Swallowing Mechanism on Neurophysiogical Basis

• Lee JK

• KMID: 2308658
• DOI: http://doi.org/10.12786/bn.2009.2.2.98

Abstract

Swallowing, known scientifically as deglutition, is the process in the human or animal body that makes something pass from the mouth, to the pharynx, into the esophagus, with the shutting of the epiglottis. If this fails and the object goes through the trachea, then choking or pulmonary aspiration can occur. In the human body it is controlled by the swallowing reflex. The nose and pharynx serves as a pathway for air in breathing. During swallowing, the pharynx is isolated from the nasal cavity and lower airway by velopharyngeal and laryngeal closure during the pharyngeal swallow. Normal swallowing process is complex neuromuscular activities consisting of three phases, an oral, pharyngeal and esophageal phase. The oral phase is usually voluntary process and mainly controlled by the fronto-temporal cerebral cortex with contributions from the motor cortex and other cortical areas. The pharyngeal phase is controlled by swallowing center in the medulla and pons. It is initiated mainly by the receptors of the posterior upper pharyngeal wall and "swallowing reflex" occurred. The food bolus is advanced from the pharynx to the esophagus through sequential contraction of the constrictor muscles. During swallowing reflex, the respiratory center of the medulla is inhibited by swallowing center accompanied by velopharyngeal and laryngeal closure to prevent airway aspiration. The esophageal phase, which is passive process, started from relaxation of upper esophageal sphincter. The autonomic system network coordinates the smooth muscles of pharynx and esophagus sequentially pushes the bolus through the esophagus into the stomach.

Keyword

physiology; swallowing; swallowing phase