The bolus is formed from the grinding of food with the teeth and saliva.
The element that is formed from the crushing of food by the action of the teeth and saliva is known as a bolus . The bolus, therefore, is the result of chewing and salivation.
When the substances present in the food are degraded and the bolus is formed, the food is prepared for swallowing and subsequent digestion . The development of the bolus, in this way, is essential for feeding .
How the bolus is formed
The step prior to the formation of the bolus is the introduction of food into the mouth . When the person begins to chew and add saliva, the food bolus is formed in their mouth. Once the bolus is prepared, the subject takes it towards the palate with the help of the tongue, and finally pushes it towards the pharynx for swallowing.
After these voluntary actions, various reflexes begin to develop. The contraction of the walls of the esophagus causes the bolus to descend into the stomach. Different mechanisms, on the other hand, allow the bolus not to pass into the airways.
In the stomach, gastric juices are responsible for continuing the decomposition of the bolus which, several hours later, becomes chyme (a type of paste). Chyme is pushed into the pylorus, then enters the small intestine and later the large intestine. When the absorption of nutrients from the chyme has occurred, the waste is transformed into feces and remains in the rectum until evacuated.
Mastication and salivation are the processes that enable the formation of the bolus.
Combination of voluntary and involuntary acts
Although it may not seem like it at first glance, the swallowing process is highly complex, since there must be infallible coordination between the muscle groups that intervene in it, located in the esophagus, larynx, pharynx and mouth.
Regarding the movement of the bolus within the body, we can distinguish between a voluntary movement (when we take it from the mouth to the pharynx) and several involuntary ones, which we carry out from that moment on throughout the swallowing process. All of this can begin either due to a stimulus from the receptors of the tongue, uvula, soft palate, larynx and pharynx, or by decision of the central nervous system .
Difficulty descending the bolus
Having said all this, there is the possibility of suffering from swallowing disorders, and one of the most important symptoms is dysphagia , that is, the difficulty in starting the process or, something even more common, the feeling that the food bolus is stuck. and does not continue descending from the neck region. If you see any of these signs, it is necessary to consult a doctor to perform the appropriate tests.
When faced with a suspected case of dysphagia, the health professional must ask the patient a series of very specific questions to avoid an erroneous diagnosis. For example, a misinterpretation of symptoms may miss the presence of globus pharyngeus , a disorder that also causes the sensation of a blockage in the throat, which can sometimes be a malignant tumor. To rule out this problem, one of the questions should be whether the sensation of obstruction in the throat disappears once the patient manages to swallow food.
Although there is not much epidemiological data in this context, it is estimated that dysphagia prevails between 3 and 9 percent in subjects over 50 years of age. Depending on the phases of the swallowing process affected, it is possible to distinguish between esophageal and oropharyngeal dysphagia; Since both its causes and consequences are different, it is essential to rule out one of the two before starting treatment.