The Excessive Gagging Reflex
Eli Ilana in Oral Psychophysiology, 2020
The gag reflex is normally activated when there is a drastic, immediate need to protect the airway and to remove noxious stimuli from the gastrointestinal tract. It is usually triggered by a stimulus in the posterior oral cavity or pharynx, in order to eructate or eliminate the stimuli.2 Gagging is associated with other reflexes of the oropharynx (i.e., swallowing and vomiting), all part of the reflexes integrated in the medulla oblongata. Swallowing is triggered by afferent impulses in the trigeminal, glossopharyngeal, and vagus nerves. The efferent fibers pass to the pharyngeal musculature and the tongue via the trigeminal, facial, and hypoglossal nerves. It is initiated by the voluntary act of propelling the oral contents toward the back of the pharynx. This starts a wave of involuntary contractions in the pharyngeal muscles that pushes the material into the esophagus. Inhibition of respiration and glottic closure are part of the swallowing reflex response.3
Head and Neck Muscles
Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo in Handbook of Muscle Variations and Anomalies in Humans, 2022
In one neonate with trisomy 13, the right posterior belly of the digastricus split and sent a deep bundle to stylopharyngeus (Colacino and Pettersen 1978). In another neonate with trisomy 13, stylopharyngeus was doubled bilaterally (Pettersen et al. 1979). The extra muscles coursed transversely to the superior pharyngeal constrictor and inserted just lateral to the pharyngeal raphe. In a boy with trisomy 13q, an extra stylopharyngeus muscle was present on the left side and inserted deep into hyoglossus (Pettersen 1979). In an infant with trisomy 18, an abnormal belly of stylopharyngeus coursed posteriorly behind the styloid process and inserted over the superficial surface of the superior constrictor (Bersu and Ramirez-Castro 1977). Stylopharyngeus was absent in a fetus with craniorachischisis (Alghamdi et al. 2017).
Oesophagus
Paul Ong, Rachel Skittrall in Gastrointestinal Nursing, 2017
As liquid enters the pharynx, the pharyngeal muscles contract and propel the bolus into the oesophagus. The laryngeal opening closes and the upper oesophageal sphincter relaxes. This allows the passage of the bolus down the oesophagus. Mechanoreceptors in the oesophageal wall sense the presence of the bolus and stimulate peristalsis. Distention of the oesophageal wall causes relaxation of the lower oesophageal sphincter, via the vagus nerve (X) and the bolus proceeds into the stomach. Air is also swallowed with the bolus and thus there are periods of transient lower oesophageal sphincter relaxations (TLOSRs) to allow the air to escape. This may allow some reflux of stomach contents.
A comparison of swallow-related submandibular contraction amplitude and duration in people with Parkinson’s disease and healthy controls
Published in International Journal of Speech-Language Pathology, 2021
Julie Kim, Christopher R. Watts
Parkinson’s disease (PD) leads to physiological impairments in the voluntary and involuntary (e.g. reflexive) actions of swallowing muscles. Oropharyngeal dysphagia occurs in more than 80% of the PD population across the progressive stages of the disease (Kalf, de Swart, Bloem, & Munneke, 2012; Pfeiffer, 2011; Simons, 2017). Pharyngeal stage swallowing impairments in PD range from delayed onset of pharyngeal stage activity, dysmotility of the pharyngeal constrictor muscles, poor base of tongue retraction, impaired laryngeal closure, and reduced opening diameter of the upper oesophageal sphincter (Leopold & Kagel, 1996; Nagaya, Kachi, Yamada, & Igata, 1998; Nilsson, Ekberg, Olsson, & Hindfelt, 1996). Numerous studies have also suggested that hyolaryngeal excursion is impaired secondary to PD (Ertekin et al., 2002; Leopold & Kagel, 1997b; Nagaya et al., 1998; Suttrup & Warnecke, 2016). Collectively these physiological impairments result in vallecular, pharyngeal wall, and/or pyriform sinus residue, in addition to laryngeal penetration with or without aspiration (Leopold & Kagel, 1997a; Suttrup & Warnecke, 2016).
Botulinum toxin A injection using ultrasound combined with balloon guidance for the treatment of cricopharyngeal dysphagia: analysis of 21 cases
Published in Scandinavian Journal of Gastroenterology, 2022
Lielie Zhu, Jiajun Chen, Xiangzhi Shao, Xinyu Pu, Jinyihui Zheng, Jiacheng Zhang, Xinming Wu, Dengchong Wu
As part of the upper oesophageal sphincter (UES), normally, the cricopharyngeal muscle maintains tension and contraction during breathing, preventing air from entering the oesophagus and protecting the airway from retrograde reflux from the stomach [1–3]. During swallowing, food is pushed from the mouth to the pharynx under the contraction of masticatory muscles, tongue muscles and pharyngeal muscles; then, the hyoid–laryngeal complex moves upwards and forwards, and the cricopharyngeal muscle relaxes physiologically to allow food to pass through [38]. This swallowing motor sequence is regulated by the medulla oblongata swallowing central pattern generator (CPG) [39]. Brain lesions of many causes, especially brainstem stroke, could damage this regulatory mechanism, which then cannot distribute the swallowing impulse to the relevant motor nucleus, resulting in cricopharyngeal muscle achalasia [38,39]. Therefore, patients with stroke were selected as the participants in this study, which has important clinical significance because of its high incidence and the high incidence of cricopharyngeal muscle achalasia after stroke [5–7,23]. In addition, with good administration, stroke can reach a relatively stable clinical state compared with other progressive neurogenic or neuromuscular diseases, which might hinder patients from gaining permanent therapeutic effects.
An update on radiation therapy in head and neck cancers
Published in Expert Review of Anticancer Therapy, 2018
Rosario Mazzola, Alba Fiorentino, Francesco Ricchetti, Fabiana Gregucci, Stefanie Corradini, Filippo Alongi
Furthermore, radiation damage to the pharyngeal constrictors and the glottic/supraglottic larynx can result in post-RT dysphagia and aspiration [24]. Thus, to prevent swallowing dysfunction, the most appropriate approach consists in reducing the dose to the pharyngeal constrictor muscles and the larynx as much as possible, by keeping in mind that target coverage remains the highest priority. Data derived from the current literature seem to suggest better swallowing outcomes with IMRT compared to 3D-RT. These findings are mainly related to the usefulness of IMRT plans optimized for swallowing structures sparing (pharyngeal constrictor muscles, supraglottic and glottis larynx, and the esophageal inlet) [7]. Anyway, regarding this last aspect, several concerns remain: (1) the heterogeneity of the cohorts analyzed (many studies focused on more than two HNC subsites); (2) the use of different swallowing questionnaires; and (3) the lack of standardized objective instrumental parameter scores.
Related Knowledge Centers
- Palatopharyngeus Muscle
- Pharynx
- Stylopharyngeus Muscle
- Esophagus
- Lumen
- Superior Pharyngeal Constrictor Muscle
- Middle Pharyngeal Constrictor Muscle
- Inferior Pharyngeal Constrictor Muscle
- Swallowing
- Salpingopharyngeus Muscle