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Current Pharmaceutical Design 2016Mastication and swallowing are the first stage of digestion involving several motor processes such as food intake, intra-oral food transport, bolus formation and chewing... (Review)
Review
Mastication and swallowing are the first stage of digestion involving several motor processes such as food intake, intra-oral food transport, bolus formation and chewing and swallowing reflex. These complicated motor functions are accomplished by the well-coordinated activities in the jaw, hyoid, tongue, facial and pharyngeal muscles. Although the basic activity patterns of these movements are controlled by the brainstem pattern generators, these movements generate various peripheral sensory inputs. Among the sensory inputs, it is well-known that somatic sensory inputs play important roles in reflexively modulating the movements so that the final motor outputs fit the environmental demand. However, little is known about the effects of chemical sensory inputs such as taste and olfaction originating from the ingested foods by these movements. A possible reason could be raised that cognition of the chemical sensory inputs at the higher brain also influences the movements, so it is difficult to discuss the neural mechanisms underlying the observed effect. In this review, we focus on the effects of chemical sensory inputs on the masticatory movements and initiation of swallowing. We first summarize chemical sensory inputs occurring during mastication and swallowing, and their receptive mechanisms. In addition, we will introduce the effect of application of monosodium L-glutamate (MSG) solution as an umami taste to the oropharynx on the swallow initiation which is involuntary controlled and the possible neural mechanisms underlying this effect is discussed.
Topics: Animals; Deglutition; Humans; Mastication; Sodium Glutamate
PubMed: 26881439
DOI: 10.2174/1381612822666160216151150 -
Dysphagia 1993Dysphagia describes the disability or problems in swallowing a wet or dry bolus properly and is normally associated with an impaired transport of the bolus. Dysphagia... (Review)
Review
Dysphagia describes the disability or problems in swallowing a wet or dry bolus properly and is normally associated with an impaired transport of the bolus. Dysphagia can be accompanied by a pain sensation in the chest mostly caused by impaction of the food bolus in the esophagus. Odynophagia describes only the status of painful swallowing without an impairment of the swallow and transport function. Drug-induced dysphagia can be caused in two different ways. First as a normal drug side effect of the pharmacological action of the drug or as a complication of the therapeutic action of the drug. The normal drug side effect is most likely in drugs that affect smooth or striated muscle function or the sensitivity of the mucosa. The drug effect on smooth muscle function that causes dysphagia can be inhibitory or excitatory. Dysphagia is a common clinical symptom in patients with reduced perception of the pharyngeal mucosa which leads to an subjective impairment of swallowing. Dysphagia caused by a complication of the therapeutic action of a drug includes viral or fungal esophagitis in patients treated with immunosuppressive drugs or cancer therapeutic agents, or antibiotics and immunological reactions to certain drugs such as erythema exsudativa multiforme or Stevens-Johnson syndrome. Second, drug-induced dysphagia can be due to medication-induced esophageal injury (MIEI). In most cases this mucosal injury appears to be the direct result of prolonged contact of a potentially caustic drug with the esophageal mucosa. This form of medication-induced esophagitis is most likely to be found in elderly patients and patients with esophageal motility disorders.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Deglutition; Deglutition Disorders; Esophagus; Humans; Pharmacology
PubMed: 8467724
DOI: 10.1007/BF02266997 -
Medical & Biological Illustration Jul 1967
Topics: Deglutition; Humans; Infant, Newborn; Radiography
PubMed: 6041477
DOI: No ID Found -
Proceedings of the Society For... 1967
Topics: Adult; Deglutition; Female; Humans; Male; Oscillometry; Sound; Spectrum Analysis
PubMed: 6042418
DOI: 10.3181/00379727-125-32300 -
Physical Medicine and Rehabilitation... Nov 2008
Topics: Deglutition; Deglutition Disorders; Humans
PubMed: 18940634
DOI: 10.1016/j.pmr.2008.08.002 -
Revista de La Federacion Odontologica... 1965
Topics: Deglutition; Humans
PubMed: 5227548
DOI: No ID Found -
Journal of Neurophysiology Jan 1956
Topics: Deglutition; Electromyography; Humans; Nervous System Physiological Phenomena; Reflex
PubMed: 13286721
DOI: 10.1152/jn.1956.19.1.44 -
Clinical Neurophysiology : Official... Dec 2003Swallowing is a complex motor event that is difficult to investigate in man by neurophysiological experiments. For this reason, the characteristics of the brain stem... (Review)
Review
UNLABELLED
Swallowing is a complex motor event that is difficult to investigate in man by neurophysiological experiments. For this reason, the characteristics of the brain stem pathways have been studied in experimental animals. However, the sequential and orderly activation of the swallowing muscles with the monitoring of the laryngeal excursion can be recorded during deglutition. Although influenced by the sensory and cortical inputs, the sequential muscle activation does not alter from the perioral muscles caudally to the cricopharyngeal sphincter muscle. This is one evidence for the existence of the central pattern generator for human swallowing. The brain stem swallowing network includes the nucleus tractus solitarius and nucleus ambiguus with the reticular formation linking synaptically to cranial motoneuron pools bilaterally. Under normal function, the brain stem swallowing network receives descending inputs from the cerebral cortex. The cortex may trigger deglutition and modulate the brain stem sequential activity. The voluntarily initiated pharyngeal swallow involves several cortical and subcortical pathways. The interactions of regions above the brain stem and the brain stem swallowing network is, at present, not fully understood, particularly in humans. Functional neuroimaging methods were recently introduced into the human swallowing research. It has been shown that volitional swallowing is represented in the multiple cortical regions bilaterally but asymmetrically. Cortical organisation of swallowing can be continuously changed by the continual modulatory ascending sensory input with descending motor output.
SIGNIFICANCE
Dysphagia is a severe symptom complex that can be life threatening in a considerable number of patients. Three-fourths of oropharyngeal dysphagia is caused by neurological diseases. Thus, the responsibility of the clinical neurologist and neurophysiologist in the care for the dysphagic patients is twofold. First, we should be more acquainted with the physiology of swallowing and its disorders, in order to care for the dysphagic patients successfully. Second, we need to evaluate the dysphagic problems objectively using practical electromyography methods for the patients' management. Cortical and subcortical functional imaging studies are also important to accumulate more data in order to get more information and in turn to develop new and effective treatment strategies for dysphagic patients.
Topics: Brain; Deglutition; Humans
PubMed: 14652082
DOI: 10.1016/s1388-2457(03)00237-2 -
Biomechanics and Modeling in... Feb 2023A FLIP device gives cross-sectional area along the length of the esophagus and one pressure measurement, both as a function of time. Deducing mechanical properties of...
A FLIP device gives cross-sectional area along the length of the esophagus and one pressure measurement, both as a function of time. Deducing mechanical properties of the esophagus including wall material properties, contraction strength, and wall relaxation from these data are a challenging inverse problem. Knowing mechanical properties can change how clinical decisions are made because of its potential for in-vivo mechanistic insights. To obtain such information, we conducted a parametric study to identify peristaltic regimes by using a 1D model of peristaltic flow through an elastic tube closed on both ends and also applied it to interpret clinical data. The results gave insightful information about the effect of tube stiffness, fluid/bolus density and contraction strength on the resulting esophagus shape through quantitive representations of the peristaltic regimes. Our analysis also revealed the mechanics of the opening of the contraction area as a function of bolus flow resistance. Lastly, we concluded that peristaltic driven flow displays three modes of peristaltic geometries, but all physiologically relevant flows fall into two peristaltic regimes characterized by a tight contraction.
Topics: Deglutition; Muscle Contraction; Esophagus; Peristalsis; Body Fluids
PubMed: 36352039
DOI: 10.1007/s10237-022-01625-x -
FP Essentials Oct 2013Swallowing occurs in 3 phases: oral, pharyngeal, and esophageal. Oropharyngeal dysphagia typically is a result of neuromuscular disorders, such as stroke and... (Review)
Review
Swallowing occurs in 3 phases: oral, pharyngeal, and esophageal. Oropharyngeal dysphagia typically is a result of neuromuscular disorders, such as stroke and parkinsonism, or of mucosal dryness caused by drugs or radiation therapy. Esophageal dysphagia is commonly caused by anatomic defects of the esophagus, such as reflux disease; motility disorders, such as achalasia; or eosinophilic esophagitis. If oropharyngeal dysphagia is suspected, the patient should undergo initial testing with a water or semisolid bolus swallow test. If results are positive, the diagnosis can be confirmed with a videofluoroscopic swallowing study. If esophageal dysphagia is suspected, patients typically undergo endoscopic esophagogastroduodenoscopy. Management of confirmed oropharyngeal dysphagia involves short-term compensation strategies, such as postural changes or food thickening, to minimize the risk of aspiration. This is followed by rehabilitation that may involve swallowing exercises with biofeedback or electrical stimulation of the swallowing muscles. Some patients may need enteral feeding. For esophageal dysphagia, choice of management depends on the etiology; it may include endoscopic dilation, myotomy, injection of onabotulinumtoxinA (formerly called botulinum toxin type A) for structural abnormalities, or topical steroid therapy for eosinophilic esophagitis.
Topics: Deglutition; Deglutition Disorders; Diagnosis, Differential; Exercise Therapy; Humans
PubMed: 24124702
DOI: No ID Found