The swallowing reflex is a foreign reflex of the human body that allows food and liquid to be absorbed. The process is also called the act of swallowing. The process is very complex and necessary for our survival.
What is the swallowing reflex?
The swallowing reflex is a foreign reflex of the human body that allows us to take in food and liquid. The swallowing reflex is innate and controlled by reflexes, or reflexes. In order to absorb and transport food, this reflex is essential. Every day, humans swallow between 1000 and 3000 times. As the food is absorbed through the oral cavity, it subsequently enters the esophagus. Swallowing is triggered by contact between the palatal arches, the tongue and the posterior pharyngeal wall. While a person swallows, breathing stops. This act is regulated by the swallowing center located in the brainstem. The act of swallowing can also be impaired and is then referred to as dysphagia. Depending on the type of food a person ingests, the swallow size and duration varies. The duration depends on how well the food has been chewed and mixed with saliva beforehand. On average, the swallowing process takes between 8 and twenty seconds.
Function and task
The swallowing process is divided into separate phases. Each of these phases has its own task to perform. The preparatory phase refers to the processes that make the actual swallowing process possible in the first place. The food must first be sufficiently chewed and mixed with saliva so that the food bolus can slide through the esophagus. The transport phase is the second step of the reflex. With the mouth closed to prevent saliva loss and to avoid swallowing additional air, the tongue presses against the palate and the swallowing process is initiated. The food bolus is conveyed into the pharynx via the pharyngeal narrowing. The muscles of the tongue provide the triggering in undulating applications. Swallowing is triggered when the base of the tongue or the posterior pharyngeal wall is touched by the food bolus. In the pharyngeal transport phase, the upper and lower airways are sealed. This prevents passage of the food bolus into the nose and possible swallowing. During swallowing, pressure equalization occurs in the middle ear and external pressure. This happens when the soft palate is tense, which also causes the Eustachian tube to dilate. If the nasopharynx is not closed during swallowing, food pulp can enter the airways. The larynx must also be closed by the epiglottis. The upper pharyngeal cords (Musculus constrictor pharyngis superior) contract and thus the closure of the airway is complete. The vocal folds are closed, the epiglottis descends, and the muscles of the floor of the mouth contract. As the larynx steps higher, the epiglottis and the laryngeal inlet close, providing triple protection of the lower airway. The upper esophageal sphincter opens and food can be transported. In the final phase, the esophageal transport phase, the muscle closes again. The food bolus has landed in the esophagus. The airway is opened again. The bolus resumes its usual course. The stomach mouth opens, and after the bolus has arrived in the stomach, it closes again. The act of swallowing is over.
Diseases and ailments
During pregnancy, the swallowing act of the child forms. However, if malformations occur in the central nervous system or in the digestive tract, the swallowing reflex is disturbed. Elderly people may also experience swallowing difficulties. Symptoms associated with dysphagia often include a lumpy feeling in the throat, gag reflex when swallowing, or coughing while eating. The causes of a present dysphagia can be a psychological cause, but also a concomitant of a neurological or chronic disease. Especially patients suffering from multiple sclerosis or ALS need to be checked. Other physical causes that affect the swallowing reflex sometimes include injuries and tumors. Often, swallowing difficulties are side effects of a severe cold or tonsillitis. Swelling of the mucous membranes makes swallowing difficult in these cases. A neurogenic disorder is the most common cause of impaired swallowing reflex.After a stroke, meningitis or a disease such as Parkinson’s disease. Swallowing difficulties also occur with muscular atrophy, a disease of the muscles. Swallowing difficulties are very common with tumors or after operations in the throat, mouth and head area. If the throat and esophagus are in contact with a foreign body for a long period of time, dysphagia sets in. The same can be caused by poisoning or chemotherapy. In younger patients, the problems are psychological. Those affected have the feeling of constantly having a lump in their throat. Children often suffer from congenital malformations. In older people, the efficiency of swallowing decreases. In presbyphagia, the reaction time of the muscles is slowed down. Tooth loss and dried mucous membranes also make swallowing difficult. Likewise, dysphagia can occur as a concomitant of dementia.
