How many stages of swallowing are there

Swallowing is dominant to respiration in normal individuals. Breathing ceases briefly during swallowing, not only because of the physical closure of the airway and neural suppression of respiration in the brainstem. There is a respiratory pause during swallowing, and respiration usually resumes with expiration. T his resumption is regarded as one of the mechanisms that prevents inhalation of food remaining in the pharynx after swallowing.

Dysphagia difficulty swallowing can result from a wide variety of functional or structural deficits at any stage of swallowing. There can be oral, pharyngeal, esophageal dysphagia or a combination. Dysphagia can result in aspiration, which is when material such as food, liquid, or saliva passes below the vocal folds into the trachea.

Consequences of dysphagia can include: pneumonia, weight loss, malnutrition, dehydration, electrolyte imbalance, psychosocial affects, alternative nutrition, hospitalization, choking, death. It is important to understand normal swallowing in order to determine if a patient has dysphagia and how to best treat it.

Patients with tracheostomy and mechanical ventilation are at high risk for dysphagia and aspiration due to many factors. All healthcare workers and individuals caring for those with tracheostomy should understand methods of preventing and controlling the transmission of infection. The novel corona virus COVID pandemic has resulted in an increase in patients intubated and use of mechanical ventilation.

The United States and globally, we are likely to see an increase in tracheostomy as well, as patients may have difficulty weaning and require longer periods of time on a vent. COVID also has implications for healthcare workers, as there are shortages with workers becoming ill from the virus.

Infection control is paramount in controlling the outbreak and protecting patients, healthcare workers and the community. Review the different types of speaking valves and benefits for those with tracheostomy and mechanical ventilation: Passy-Muir, Shiley, Shikani, and Montgomery.

Assessment, trouble-shooting and advanced placement techniques of a speaking valve in-line with mechanical ventilation. This information has been collected and designed to help in clinical management, the authors do not accept any responsibility for any harm, loss or damage arising from actions or decisions based on the information contained within this website and associated publications.

The opinions expressed are those of the authors. Gastro esophageal reflux is among the top common causes of dysphagia. Discomfort is caused from the stomach acid moving up the esophagus to the pharynx. Other medical issues that causes swallowing difficulty include hypertension; diabetes; thyroid disease; stroke; progressive neurologic disorder; the presence of a tracheotomy tube; a paralyzed or unmoving vocal cord; a tumor in the mouth, throat, or esophagus; or surgery in the neck, head, or esophageal areas.

Depending on the cause dictates treatment. Medications, a change in eating habits, eliminate alcohol, caffeine, and tobacco products, reduce weight and stress, keeping the head elevated during sleep, swallowing therapy, and surgery are all various methods and are used in accordance to why you are having problems swallowing.

If you are having problems swallowing, call ENT Specialists and let our medical professionals help diagnose the underlying problem and prescribe treatment accordingly. The UES remains closed passively because of the surrounding structures and tonic contraction of the cricopharyngeus muscle as a result of tonic activity of the nerves innervating it.

In contrast, the LES remains closed largely because of the unique property of its muscle. The swallowing reflex is an elaborate involuntary reflex that involves a swallowing center, or a swallowing pattern generator, in the brainstem. Once activated, the swallowing center neurons send patterned discharges of inhibition and excitation to motor nuclei of the cranial nerves.

Pharyngeal and esophageal peristalsis mediated by the swallowing reflex is known as primary peristalsis. The peristaltic contraction in the striated muscles of the pharynx and thoracic esophagus is the result of sequential inhibition followed by excitation of muscles that are involved in generating peristaltic contraction.

The premotor nucleus that mediates swallowing is the central nucleus of the solitary tract that sends fibers to the nucleus ambiguous of the vagus.

The neural mechanism of primary peristaltic contraction in the smooth muscle of the thoracic esophagus is orchestrated by the premotor neurons in solitary tract, which send projections to the caudal and rostral parts of the dorsal motor nucleus of vagus.

The caudal part of the dorsal motor nucleus of vagus contains neurons of the inhibitory pathway to the esophagus, whereas the rostral part houses the excitatory pathway neurons to the esophagus. The inhibitory pathway neurons are activated first; this results in inhibition of all ongoing activity in the esophagus and relaxation of the LES.

This is followed by sequential activation of neurons to distal areas of the esophagus. The sequence of inhibition followed by excitation can be documented with membrane potential studies as a wave of hyperpolarization followed by depolarization.

The peristaltic behavior is the result of a progressive increase in the duration of hyperpolarizations aborally along the esophagus. The gradient of increasing inhibition distally along the esophagus that precedes peristaltic contraction is also called the latency gradient, or deglutitive inhibition.

When a subject is drinking, swallows occur in rapid succession at rates of one swallow every 2 seconds. Under these circumstances, the pharyngeal response follows each swallow, but the esophagus remains inhibited until the last swallow that is followed by peristaltic contraction. The loss of deglutitive inhibition results in nonperistaltic contractions that are sometimes called tertiary contractions. Swallowing is a highly regulated activity. Normally, it is activated by peripheral receptors located on structures in the posterior part of the oral cavity and oropharynx that are stimulated as the food bolus is pushed into the oropharynx.

Afferents in the superior laryngeal nerves are important stimulators of the swallowing reflex. The cranial nerves involved in coordinating this stage include the trigeminal nerve, the facial nerve, and the hypoglossal nerve. As the food bolus reaches the pharynx, special sensory nerves activate the involuntary phase of swallowing.

The swallowing reflex, which is mediated by the swallowing center in the medulla the lower part of the brainstem , causes the food to be further pushed back into the pharynx and the esophagus food pipe by rhythmic and involuntary contractions of several muscles in the back of the mouth, pharynx, and esophagus.

Because the mouth and throat serve as an entryway for both food and air, the mouth provides a route for air to get into the windpipe and into the lungs, and it also provides a route for food to get into the esophagus and into the stomach.

A critical part of the pharyngeal phase is the involuntary closure of the larynx by the epiglottis and vocal cords, and the temporary inhibition of breathing. The closure of the larynx by the epiglottis protects the lungs from injury, as food and other particles that enter into the lungs can lead to severe infections and irritation of the lung tissue.

Lung infections caused by problems with the pharyngeal phase of the swallowing reflex are commonly known as aspiration pneumonia. As food leaves the pharynx, it enters the esophagus, a tube-like muscular structure that leads food into the stomach due to its powerful coordinated muscular contractions.

The passage of food through the esophagus during this phase requires the coordinated action of the vagus nerve , the glossopharyngeal nerve, and nerve fibers from the sympathetic nervous system. The esophagus has two important muscles that open and close reflexively as the food bolus is brought down during swallowing.

These muscles, called sphincters, allow the food bolus to flow in a forward direction while preventing it from going in the wrong direction regurgitation. Both esophageal sphincters, first the upper, and then the lower, open in response to the pressure of the food bolus and close after the food bolus passes.

The upper esophageal sphincter prevents food or saliva from being regurgitated back into the mouth, while the lower esophageal sphincter ensures that food remains in the stomach, preventing regurgitation back into the esophagus. In doing so, the esophageal sphincters serve as a physical barrier to regurgitated food. In general, healthy people can swallow with very little deliberate thought and effort.

If the nervous system is disrupted due to a stroke or another disease, then problems with swallowing can occur. Swallowing difficulties are referred to as dysphagia.