Internal Superior Laryngeal Nerve Research Articles

Stimulation of the internal superior laryngeal nerve as a potential therapy for obstructive sleep apnea in a porcine model.

Impaired pharyngeal sensing of negative pressure (NP) can lead to a blunted response of the upper airway dilator muscles and contribute to the development of obstructive sleep apnea (OSA). This response is modulated by the nerve fibers in the internal branch of the superior laryngeal nerve (iSLN), mediating negative pressure sensation. Artificial excitation of these fibers could be a potential treatment target for OSA. To evaluate this, electrostimulation of the iSLN was performed in a porcine-isolated upper airway model. Artificial obstructions were induced by varying the levels of negative pressure, and the ability of the animal to resolve these obstructions was evaluated. The pressure at which the animal was still able to resolve the obstruction was quantified as "Resolvable Pressure." Thereby, the effects on pharyngeal patency (n = 35) and the duration of the therapeutic effect outlasting the stimulation (n = 6) were quantified. Electrostimulation before the introduction of an artificial obstruction improved the median resolvable pressure from -28.3 cmH2O [IQR: -45.9; -26.1] to -92.6 cmH2O [IQR: -105.1; -78.6]. The median therapeutic effect was found to outlast the last stimulation burst applied by 163 s when five stimulation bursts were applied in short succession [IQR: 58; 231], 58 s when two were applied [IQR: 7; 65], and 6 s when one was applied [IQR: 0; 51]. Stimulation of the iSLN increased electromyography (EMG) in the genioglossus (GG). The proposed treatment concept can improve pharyngeal patency in the model. Transfer of the results to clinical application could enable the development of a new neuromodulation therapy for OSA.NEW & NOTEWORTHY Electrostimulation before the introduction of an artificial obstruction to induce artificial sleep apnea in the pig model improves the response of the upper airway to negative pressure (NP). The electrostimulation creates a sustained therapeutic effect that outlasts the initial electrostimulation. The use of this therapy in clinical practice has the potential to treat obstructive sleep apnea (OSA).

Effect of postoperative ultrasound-guided internal superior laryngeal nerve block on sore throat after intubation of double-lumen bronchial tube: a randomized controlled double-blind trial

BackgroundPostoperative sore throat (POST) is one of the main adverse postoperative outcome after tracheal intubation using double-lumen endobronchial tubes (DLTs). The aim of this study was to investigate the effectiveness and safety of ultrasound (US)-guided block of the internal branch of the superior laryngeal nerve (iSLN) for alleviating POST after intubation of DLTs.MethodsPatients undergoing thoracic surgery between August 2019 and August 2021 were randomized into two groups depending on whether they received US-guided iSLN block immediately after the operation. In the control group, the patients underwent a thoracic surgery under general anesthesia (GA) with DLTs without any special treatment, while the patients in the experimental group received US-guided iSLN block bilaterally with 2 ml of 0.25% ropivacaine on either side immediately after the operation. The primary outcome was the grading of sore throat at three-time points after the operation, i.e., immediate extubation, 2 h after extubation, and 24 h after extubation. Secondary outcomes included the rate of nausea and vomiting, hoarseness, dyspnea, and choking cough after swallowing saliva at 2 h after extubation.ResultsThe incidence and severity of sore throat were significantly lower in the experimental group than the control group at all time intervals (all P < 0.01). The rate of nausea and vomiting, hoarseness, dyspnea, and choking cough after swallow saliva at 2 h after extubation had no statistical difference (all P > 0.05).ConclusionsThe use of US-guided iSLN block can be effectively and safely applied to relieve POST after intubation of DLTs on thoracic surgery.Trial registrationThe study protocol was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn, NO. ChiCTR2000032188, 22/04/2020).

Clinical anatomy of superior laryngeal artery via transoral approach.

ObjectiveHemorrhage is the most common complication caused by transoral laryngopharyngeal surgery. It is believed that proper management of the superior laryngeal artery (SLA), the main feeding artery for the larynx and pharynx, may reduce intra‐ and postoperative hemorrhage incidence. The aim of this study was to illustrate the anatomy of the SLA via transoral endoscopic approach.MethodsFourteen sides of SLA from heads of seven fresh‐frozen and silicone‐injected cadavers were dissected. Transoral dissections were performed for the intra‐laryngeal segment of SLA, and transcervical dissections were performed to confirm the anatomical measurements.ResultsSLA had a slightly descending course from the origin to the larynx, and there was a major branch supplying the epiglottis, named pharyngo‐epiglottic artery (PEA). Parallel with the internal superior laryngeal nerve (ISLN), SLA passed through the thyrohyoid membrane and ended into the hypopharynx. The distance from SLA to the superior horn of thyroid cartilage (SHTC) was (9.11 ± 0.58)mm on the left and (9.01 ± 0.37)mm on the right; the distance from SLA to the inferior margin of the hyoid bone (IMHB) was (2.00 ± 0.11)mm on the left and (1.95 ± 0.08)mm on the right; the distance from SLA to ISLN was (5.98 ± 0.48)mm on the left and (5.78 ± 0.36)mm on the right. No significant difference was found between bilateral sides (p > 0.05). Moreover, the distance from SLA to superior margin of thyroid cartilage (SMTC) was (5.52 ± 0.24)mm on the left and (5.80 ± 0.15)mm on the right. A significant difference was also found between bilateral sides (p = 0.03), which might suggest the SLA is located further from the SMTC on the right side.ConclusionSHTC, SMTC, and IMHB could be regarded as anatomical landmarks to locate SLA when applying a transoral approach. Moreover, a complete understanding of the detailed anatomy of the superior laryngeal artery may improve the detection of hemostasis in transoral laryngeal or hypo‐pharyngeal surgery.

Awake tracheal intubation during the COVID-19 pandemic - an aerosol-minimising approach.

We recently needed to perform awake tracheal intubation (ATI) for a patient undergoing urgent maxillofacial surgery at our secondary hospital. During the coronavirus disease 2019 (COVID-19) pandemic all maxillofacial surgery patients are treated as suspected COVID-19 and ATI is widely regarded as high-risk for aerosol generation. We sought early multidisciplinary input and were informed by Ahmad et al.’s recent case report [1]. Our operating theatres have positive-pressure airflow. Negative-pressure rooms are available elsewhere in the hospital but we felt managing a difficult airway in an unfamiliar environment posed significant risk. Our available personal protective equipment comprised a disposable gown; N95 mask; goggles; full-face shield; and double gloves. We administered glycopyrrolate intravenously and used a topicalisation process designed to minimise aerosol generation: Pacey’s paste to the posterior tongue [2]; lidocaine 10% sprays to the oropharynx; lidocaine 4% via a mucosal atomiser device; and internal superior laryngeal nerve blocks using lidocaine 4%-soaked gauze and Jackson laryngeal forceps [3]. Following Difficult Airway Society guidelines [4], the total dose of lidocaine administered was < 9 mg.kg-1 (lean body weight) and a second anaesthetist administered remifentanil for conscious sedation by target-controlled infusion at 2 ng.ml−1. Oxygen 4 l.min−1 was given via Hudson mask with end-tidal carbon dioxide monitoring and a cut-out permitting oral access. Excellent topicalisation was achieved. First-pass orotracheal intubation was performed without complication using a disposable Ambu® aScope™ 4 Broncho size Regular (Ambu A/S, Ballerup, Denmark). A Shiley™ Lo-Contour flexible reinforced endotracheal tube of size 7.0 mm (Covidien Ireland Limited, Tullamore, Ireland) was used and the tracheal tube cuff was gently inflated before the induction of anaesthesia. We describe an effective aerosol-minimising approach to ATI. This process varied from our usual practise which typically includes high-flow nasal oxygen, the EZ-100m™ disposable atomiser (Alcove Medical inc., Houston, TX, USA) nasotracheal intubation and cuff inflation after induction of anaesthesia – these were avoided due COVID-19 aerosolisation concerns. Published with the written consent of the patient. No external funding or competing interests declared.

Unearthing a consistent bilateral R1 component of the laryngeal adductor reflex in awake humans.

The laryngeal adductor reflex (LAR) is an essential tracheobronchial protective mechanism resulting in vocal fold adduction to laryngeal stimulation. It was thought to consist of an early ipsilateral R1 component and a later, bilateral but highly centrally modulated R2 component. We recently demonstrated that bilateral R1 responses are robustly present in humans under general anesthesia. We herein give evidence that the R1 response is also bilateral in awake humans and is likely the primary component responsible for initiating the LAR. Seven volunteers were included (3 males, 4 females). The reflex was elicited by direct percutaneous monopolar needle stimulation of the internal superior laryngeal nerve. Electromyography traces from bilateral lateral cricoarytenoid muscles were recorded using hookwire electrodes. Reflex responses to variations in stimulus intensity and duration were evaluated. Bilateral R1 responses were recorded in all patients, even during deep inspiration when the vocal folds were maximally abducted. R1, but not R2, responses increased linearly in amplitude, with sequential increases in both stimulation intensity (1-8 mA) and duration (100-500 µsec) (Pearson correlation 0.94). Contradicting over 40 years of research, we demonstrate that the R1 LAR component is consistently bilateral in awake humans. It increases linearly with stimulus intensity and is unaffected by conscious state suggesting minimal central control. These findings may provide a means to objectively stratify patients for risk of laryngeal aspiration, even in unconscious states, and its potentially cardinal role in disease states such as laryngospasm and sudden infant death needs to be reevaluated. 4. Laryngoscope, 2581-2587, 2018.

Effects of transcutaneous electrical stimulation on vocal folds adduction.

According to most previous studies, inducing movements in internal laryngeal muscles by transcutaneous electrical stimulation (TES) was impossible. However, the movements have been reported after using needle electrodes inserted into the internal superior laryngeal nerve (ISLN). Herein, we aimed to apply an innovative TES protocol to cause movements in vocal folds. A short duration and high frequency electrical current was applied by two surface electrodes just above the entrance of ISLN to larynx. The subjects were 32 normal participants (mean age=23.87; SD=3.43). During TES application, the vocal folds' movements were examined by flexible videonasolaryngoscopy. Statistical paired t test was used to analyze the differences of vocal folds opening angle, in degrees, during rest and TES periods. Furthermore, the movements were judged by seven experienced speech pathologists via a 9-point rate scale from -1 (any abduction) to 8 (complete adduction). The mean vocal folds adduction increased by 35.68° (t=9.35, p>0.001) due to TES application. The mean qualitative scores assigned by raters to each subject were between 6 and 7 points, which indicate an acceptable adduction in vocal folds through TES. Unlike previous studies, the applied TES protocol in this research induced significant vocal fold movements. This might be attributed to our different stimulation parameters, which were designed to penetrate deeply and stimulate ISLN specifically. It is worth noting that we introduced a novel TES protocol, which should be confirmed and then examined as a complementary therapy for neurologic voice disorders in future studies.

Parkinson Disease Affects Peripheral Sensory Nerves in the Pharynx

Dysphagia is very common in patients with Parkinson disease (PD) and often leads to aspiration pneumonia, the most common cause of death in PD. Current therapies are largely ineffective for dysphagia. Because pharyngeal sensation normally triggers the swallowing reflex, we examined pharyngeal sensory nerves in PD patients for Lewy pathology.Sensory nerves supplying the pharynx were excised from autopsied pharynges obtained from patients with clinically diagnosed and neuropathologically confirmed PD (n = 10) and healthy age-matched controls (n = 4). We examined the glossopharyngeal nerve (cranial nerve IX), the pharyngeal sensory branch of the vagus nerve (PSB-X), and the internal superior laryngeal nerve (ISLN) innervating the laryngopharynx. Immunohistochemistry for phosphorylated α-synuclein was used to detect Lewy pathology. Axonal α-synuclein aggregates in the pharyngeal sensory nerves were identified in all of the PD subjects but not in the controls. The density of α-synuclein-positive lesions was greater in PD patients with dysphagia versus those without dysphagia. In addition, α-synuclein-immunoreactive nerve fibers in the ISLN were much more abundant than those in cranial nerve IX and PSB-X. These findings suggest that pharyngeal sensory nerves are directly affected by pathologic processes in PD. These abnormalities may decrease pharyngeal sensation, thereby impairing swallowing and airway protective reflexes and contributing to dysphagia and aspiration.

Bilateral Internal Superior Laryngeal Nerve Palsy of Traumatic Cervical Injury Patient Who Presented as Loss of Cough Reflex after Anterior Cervical Discectomy with Fusion

Injury to the bilateral internal branch of superior laryngeal nerve (ibSLN) brings on an impairment of the laryngeal cough reflex that could potentially result in aspiration pneumonia and other respiratory illnesses. We describe a patient with traumatic cervical injury who underwent bilateral ibSLN palsy after anterior cervical discectomy with fusion (ACDF). An 75-year-old man visited with cervical spine fracture and he underwent ACDF through a right side approach. During the post-operative days, he complained of high pitched tone defect, and occasional coughing during meals. With a suspicion of SLN injury and for the work up for the cause of aspiration, we performed several studies. According to the study results, he was diagnosed as right SLN and left ibSLN palsy. We managed him for protecting from silent aspiration. Swallowing study was repeated and no evidence of aspiration was found. The patient was discharged with incomplete recovery of a high pitched tone and improved state of neurologic status. The SLN is an important structure; therefore, spine surgeons need to be concerned and be cautious about SLN injury during high cervical neck dissection, especially around the level of C3-C4 and a suspicious condition of a contralateral nerve injury.

Clinically Relevant Anatomy of High Anterior Cervical Approach

An anatomic study of anterior cervical dissection of 11 embalmed cadavers and measurement of structures relative to cervical spine. To determine the anatomic relationship of the hypoglossal nerve (HN), internal and external superior laryngeal nerves (ESLNs), superior thyroid artery (STA), and superior laryngeal artery (SLA) to cervical spine and demonstrate any vulnerability. The anterior approach is a common approach to the cervical spine. Much of the operative morbidity in high cervical region is related to neurovascular injury leading to dysphagia, dysphonia, impaired high-pitch phonation, and impaired cough reflex. Eleven adult cadavers (5 male/6 female) were dissected bilaterally to expose structures of the high anterior cervical region. The HN consistently traveled toward the midline at C2-3 and was safe caudal to C3-4. In 95% of dissections, the internal superior laryngeal nerve (ISLN) was exposed within 1 cm of C3-4. The path of the ESLN was variable, but it was safe above C3-4 and below C6-7. The ESLN was deep to the STA, and it was less bulky and tauter than the ISLN in all dissections. The origin of the STA was quite variable along the carotid artery, but it was most commonly located at C4. Two anatomic variants of the SLA were observed. In 15 dissections, the SLA branched off the superior thyroid. In six dissections, the SLA branched directly from external carotid artery. There was no appreciable side-to-side variation in the neurovascular structures studied. On the basis this study, spine surgeons can have enhanced knowledge of high anterior cervical anatomy. The neurovascular structures in this study did not demonstrate side-to-side anatomic variation; therefore, patient pathology and surgeon preference should dictate the operative side.

The Pars Interna/Media Anatomy and Histology in the Human Larynx

The pars interna/media (PIM) is a small muscle found in the human larynx that has not been successfully described in contemporary literature on laryngeal structure. The objective of this study was to describe the PIM’s anatomy in detail. Thirteen human larynges obtained from postmortem examination were cleaned and preserved. Exposure of the PIM was through a lateral disarticulation of the cricothyroid joint and reflection of the cricothyroid muscle and the thyroid lamina. In the human, the PIM was found to be strap-like in form and to have two bellies with attachments to the medial surface of the thyroid cartilage at the root of the inferior horn and anteriosuperior cricoid arch. It appears to be innervated by a middle division, vestibular branch, of the internal superior laryngeal nerve. The average fiber diameter is 40 µm. Its type 1-to-type 2 fiber ratio places it within the range of other intrinsic laryngeal muscles. A muscle spindle was identified in medial bundle at the PIM’s thyroid attachment. Thyroid medial surface attachment is within few millimeters of the muscular process of the arytenoid cartilage. These data show that the PIM is a robust muscle and deserves attention anatomically. Its orientation within the thyroid and nonrecurrent laryngeal nerve innervations of the human PIM may place it in the vocal fold tensor group rather than the laryngeal sphincter group. It is possible the PIM reports on cricothyroid distance and right versus left cricothyroid joint stresses. Electromyographic examination of the PIM in the Rhesus larynx may help elucidate its physiology to elaborate its human physiology.

Sensory regulation of swallowing and airway protection: a role for the internal superior laryngeal nerve in humans.

During swallowing, the airway is protected from aspiration of ingested material by brief closure of the larynx and cessation of breathing. Mechanoreceptors innervated by the internal branch of the superior laryngeal nerve (ISLN) are activated by swallowing, and connect to central neurones that generate swallowing, laryngeal closure and respiratory rhythm. This study was designed to evaluate the hypothesis that the ISLN afferent signal is necessary for normal deglutition and airway protection in humans. In 21 healthy adults, we recorded submental electromyograms, videofluoroscopic images of the upper airway, oronasal airflow and respiratory inductance plethysmography. In six subjects we also recorded pressures in the hypopharynx and upper oesophagus. We analysed swallows that followed a brief infusion (4-5 ml) of liquid barium onto the tongue, or a sip (1-18 ml) from a cup. In 16 subjects, the ISLN was anaesthetised by transcutaneous injection of bupivacaine into the paraglottic compartment. Saline injections using the identical procedure were performed in six subjects. Endoscopy was used to evaluate upper airway anatomy, to confirm ISLN anaesthesia, and to visualise vocal cord movement and laryngeal closure. Comparisons of swallowing and breathing were made within subjects (anaesthetic or saline injection vs. control, i.e. no injection) and between subjects (anaesthetic injection vs. saline injection). In the non-anaesthetised condition (saline injection, 174 swallows in six subjects; no injection, 522 swallows in 20 subjects), laryngeal penetration during swallowing was rare (1.4 %) and tracheal aspiration was never observed. During ISLN anaesthesia (16 subjects, 396 swallows), all subjects experienced effortful swallowing and an illusory globus sensation in the throat, and 15 subjects exhibited penetration of fluid into the larynx during swallowing. The incidence of laryngeal penetration in the anaesthetised condition was 43 % (P < 0.01, compared with either saline or no injection) and of these penetrations, 56 % led to tracheal aspiration (without adverse effects). We further analysed the swallow cycle to evaluate the mechanism(s) by which fluid entered the larynx. Laryngeal penetration was not caused by premature spillage of oral fluid into the hypopharynx, delayed clearance of fluid from the hypopharynx, or excessive hypopharyngeal pressure generated by swallowing. Furthermore, there was no impairment in the ability of swallowing to halt respiratory airflow during the period of pharyngeal bolus flow. Rather, our observations suggest that loss of airway protection was due to incomplete closure of the larynx during the pharyngeal phase of swallowing. In contrast to the insufficient closure during swallowing, laryngeal closure was robust during voluntary challenges with the Valsalva, Müller and cough manoeuvres under ISLN anaesthesia. We suggest that an afferent signal arising from the ISLN receptor field is necessary for normal deglutition, especially for providing feedback to central neural circuits that facilitate laryngeal closure during swallowing. The ISLN afferent signal is not essential for initiating and sequencing the swallow cycle, for co-ordinating swallowing with breathing, or for closing the larynx during voluntary manoeuvres.

Internal superior laryngeal nerve afferent activity during respiration and evoked vocalization in cats.

The purpose of this project was to identify and categorize patterns of activity of the internal branch of the superior laryngeal nerve during vocalization evoked by midbrain stimulation in cats anesthetized with alpha-chloralose. Unit activity was isolated from the cut distal end of the internal branch of the superior laryngeal nerve by means of floating bipolar electrodes that retained their contact with nerve fibers despite movement due to vocalization. The phases of respiration and vocalization were determined with a diaphragm electromyogram, a photoglottogram, and a microphone recording. Five groups of discrete afferent activities were defined according to relationships between the spike activity and the phases of vocalization. Group 1 cell activity peaked just before phonation, during expiratory airflow (n = 26). Group 2 cells (n = 19) followed a vocal fold vibratory pattern during phonation. Group 3 cell activity (n = 6) peaked during phonation, but did not follow vocal fold vibration. Group 4 cells (n = 3) were active during inspiration between phonations. Group 5 cells (n = 4) showed both inspiratory and expiratory modulation. These results indicate that laryngeal afferent activity responds to phonation-specific events during vocalization. This stereotyped afferent information might be used by the central nervous system to modulate vocalization.

Sensory nerve supply of the human oro- and laryngopharynx: a preliminary study.

To date, the details of human sensory innervation to the pharynx and upper airway have not been demonstrated. In this study, a single human oro- and laryngopharynx obtained from autopsy was processed with a whole-mount nerve staining technique, Sihler's stain, to determine its entire sensory nerve supply. The Sihler's stain rendered all mucosa and soft tissue translucent while counterstaining nerves. The stained specimen was then dissected and the nerves were traced from their origins to the terminal branches. It was found that the sensory innervation of the human pharynx is organized into discrete primary branches that innervate specific areas, although these areas are often connected by small neural anastomoses. The density of innervation varied, with some areas receiving almost no identifiable nerve supply (e.g., posterior wall of the hypopharynx) and certain areas contained much higher density of sensory nerves: the posterior tonsillar pillars; the laryngeal surface of the epiglottis; and the postcricoid and arytenoid regions. The posterior tonsillar pillar was innervated by a dense plexus formed by the pharyngeal branches of the IX and X nerves. The epiglottis was densely innervated by the internal superior laryngeal nerve (ISLN) and IX nerve. Finally, the arytenoid and postcricoid regions were innervated by the ISLN. The postcricoid region had higher density of innervation than the arytenoid area. The use of the Sihler's stain allowed the entire sensory nerve supply of the pharyngeal areas in a human to be demonstrated for the first time. The areas of dense sensory innervation are the same areas that are known to be the most sensitive for triggering reflex swallowing or glottic protection. The data would be useful for further understanding swallowing reflex and guiding sensory reinnervation of the pharynx to treat neurogenic dysphagia and aspiration disorders.

Anatomy of the human internal superior laryngeal nerve.

The mucosa of the larynx contains one of the most dense concentrations of sensory receptors in the human body. This sensitivity is used for reflexes that protect the lungs, and even momentary loss of this function is followed rapidly by life-threatening pneumonia. The internal superior laryngeal nerve (ISLN) supplies the innervation to this area, and, to date, the distribution and branching pattern of this nerve is unknown. Five adult human larynges were processed by using Sihler's stain, a technique that clears soft tissue while counterstaining nerves. The whole-mount specimens were then dissected to demonstrate the branching of the ISLN from its main trunk down to the level of terminal axons. The human ISLN is divided into three divisions: The superior division supplies mainly the mucosa of the laryngeal surface of the epiglottis; the middle division supplies the mucosa of the true and false vocal folds and the aryepiglottic fold; and the inferior division supplies the mucosa of the arytenoid region, subglottis, anterior wall of the hypopharynx, and upper esophageal sphincter. Several dense sensory plexi that cross the midline were seen on the laryngeal surface of the epiglottis and arytenoid region. The human ISLN also appears to supply motor innervation to the interarytenoid (IA) muscle. A detailed map is presented of the distribution of the ISLN within the human larynx. The areas seen to receive the greatest innervation are the same areas that have been shown by physiological experiments to be the most sensate: the laryngeal surface of the epiglottis, the false and true vocal folds, and the arytenoid region. The observation that the human ISLN appears to supply motor innervation to the IA muscle is contrary to current concepts of the ISLN as a purely sensory nerve. These findings are relevant to understanding how the laryngeal protective reflexes work during activities like swallowing. The nerve maps can be used to guide surgical attempts to reinnervate the laryngeal mucosa when sensation is lost due to neurological disease.

Deglutition.

Deglutition.

SOME FUNCTIONAL CHARACTERISTICS OF MECHANORECEPTORS IN THE LARYNX OF THE CAT.

ArticlesSOME FUNCTIONAL CHARACTERISTICS OF MECHANORECEPTORS IN THE LARYNX OF THE CATS. Sampson, and C. EyzaguirreS. Sampson, and C. EyzaguirrePublished Online:01 May 1964https://doi.org/10.1152/jn.1964.27.3.464MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByLiquiritin apioside attenuates laryngeal chemoreflex but not mechanoreflex in rat pupsWan Wei, Xiuping Gao, Lei Zhao, Jianguo Zhuang, Yang Jiao, and Fadi Xu18 December 2019 | American Journal of Physiology-Lung Cellular and Molecular Physiology, Vol. 318, No. 1Sensory Regulation of Swallowing and Airway Protection: A Role for the Internal Superior Laryngeal Nerve in Humans1 July 2003 | The Journal of Physiology, Vol. 550, No. 1Mucosal afferents mediate laryngeal adductor responses in the catRichard D. Andreatta, Eric A. Mann, Christopher J. Poletto, and Christy L. Ludlow1 November 2002 | Journal of Applied Physiology, Vol. 93, No. 5I. Internal Superior Laryngeal Nerve Afferent Activity during Respiration and Evoked Vocalization in Cats4 December 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 110, No. 7_supplII. Effect of Recurrent Laryngeal Nerve Paralysis on Superior Laryngeal Nerve Afferents during Evoked Vocalization4 December 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 110, No. 7_supplInhibition of inspiratory motor output by high‐frequency low‐pressure oscillations in the upper airway of sleeping dogs8 September 2004 | The Journal of Physiology, Vol. 517, No. 1Recording from Afferents in the Intact Recurrent Laryngeal Nerve during Respiration and Vocalization28 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 107, No. 9The respiratory activity of the superior laryngeal nerve in the ratRespiration Physiology, Vol. 86, No. 3Afferent Activity in the External Branch of the Superior Laryngeal and Recurrent Laryngeal Nerves28 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 100, No. 11Response characteristics of lamb trigeminal neurons to stimulation of the oral cavity and epiglottis with different sensory modalitiesBrain Research Bulletin, Vol. 22, No. 5Response properties of fibers in the hamster superior laryngeal nerveBrain Research, Vol. 450, No. 1-2Characteristics of laryngeal cold receptorsRespiration Physiology, Vol. 71, No. 3Diuresis mediated by the superior laryngeal nerve in ratsPhysiology & Behavior, Vol. 44, No. 3Autoradiographic demonstration of the distribution of vagal afferent nerve fibers in the epiglottis of the rabbitBrain Research, Vol. 410, No. 1Laryngeal afferents activated by phenyldiguanide and their response to cold air or helium-oxygenRespiration Physiology, Vol. 67, No. 3Effect of cold air on laryngeal mechanoreceptors in the dogRespiration Physiology, Vol. 64, No. 1Role of intrinsic muscles and tracheal motion in modulating laryngeal receptorsRespiration Physiology, Vol. 61, No. 3Laryngeal cold receptorsRespiration Physiology, Vol. 59, No. 1Afferent pathways for hypoglossal and phrenic responses to changes in upper airway pressureRespiration Physiology, Vol. 55, No. 3Receptors responding to changes in upper airway pressureRespiration Physiology, Vol. 55, No. 3Laryngeal receptors responding to transmural pressure, airflow and local muscle activityRespiration Physiology, Vol. 54, No. 3Effects of prostaglandins E1 and E2 on activity in laryngeal and pharyngeal afferent fibersProstaglandins, Vol. 17, No. 4Low level potentiation of the brain stem laryngeal reflexBrain Research Bulletin, Vol. 1, No. 4Laryngeal Phonatory Reflex28 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 84, No. 2Anatomical and functional differentiation of superior laryngeal nerve fibers affecting swallowing and respirationExperimental Neurology, Vol. 42, No. 2Reflex effects of chemical irritation of the upper airways on the laryngeal lumen in catsRespiration Physiology, Vol. 18, No. 1Presynaptic excitability changes induced in single laryngeal primary afferent fibresBrain Research, Vol. 53, No. 2Arterial Baroreceptor Fibers in the Recurrent Laryngeal Nerve29 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 82, No. 2Periodontal and facial influences on the laryngeal input to the brain stem of the catArchives of Oral Biology, Vol. 17, No. 11Significance of sensory inflow to the swallowing reflexBrain Research, Vol. 43, No. 1The neurology of stammeringJournal of Psychosomatic Research, Vol. 15, No. 4Mechanosensory units in the hypoglossal nerve of the catBrain Research, Vol. 32, No. 2Modulation of laryngeal activity by pulmonary changes during vocalization in catsExperimental Neurology, Vol. 29, No. 2II Sensory Fibers in the Recurrent Laryngeal Nerve28 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 78, No. 1LXXXVII Afferent Nerve Fibers in the External Branch of the Superior Laryngeal Nerve in the Cat29 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 77, No. 6A functional analysis of sensory units innervating epiglottis and larynxExperimental Neurology, Vol. 20, No. 3LIX Laryngeal Reflex Pathways Related to Rate and Rhythm of the Heart28 June 2016 | Annals of Otology, Rhinology & Laryngology, Vol. 76, No. 4Bibliography on muscle receptors; Their morphology, pathology and physiologyExperimental Neurology, Vol. 18 More from this issue > Volume 27Issue 3May 1964Pages 464-480 https://doi.org/10.1152/jn.1964.27.3.464PubMed14170133History Published online 1 May 1964 Published in print 1 May 1964 Metrics

Electromyographic Study on the Cervical Esophagus in Dog

Electrical activity of the esophageal muscle in dog was studied with a view in elucidating the nature of nervous innervation.In resting phase esophageal muscle was kept quiescent and no muscle activity could be recorded. To obtain action potential by direct stimulation more intensive stimulus was required than the other skeretal muscles in the neck. The muscle responses induced by stimulation of the recurrent laryngeal nerve had variable time delay ranged from 2 to 10 msec. These results might be the consequence of either variable fiber size contained in the efferent nerve or mode of distribution of the endplate in the muscles.A reflex response in the esophageal muscle was evoked by stimulation of the internal superior laryngeal nerve. A response was a asynchronous type with a latency of about 20 msec.A relatively long latency and the repetitive nature of the discharge indicated that a response should be a polysynaptic reflex.Sometimes stimulation of the recurrent laryngeal nerve evoked, besides a direct response from the muscle, a secondary response of considerably lower amplitude after an interval of about 20 msec.The origin and nature of a secondary response were discussed.

An electromyographic analysis of reflex deglutition.

An electromyographic analysis of reflex deglutition.