Deglutition is also known as ‘Swallowing’, it is the process by which the food taken passing through the oral cavity into the Gastrointestinal tract.
The Number of times a person or individual swallows per day: 600 times
Deglutition is divided into 3 stages:
- Oral stage
- Pharyngeal stage
- Esophageal stage.
The stages are divided into Voluntary and Involuntary stages
- Pharyngeal stage
- Esophageal stage
This stage is after mastication of the food is completed, te masticated food is known as Bolus, this bolus is placed on the posterior surface of the tongue by suitable movements of the tongue, Then the soft palate raises and seals of the nasopharynx, to prevent the food from entering into the nasal cavity, now the respirtion reflex is stopped, then the anterior part of the tongue is raised which causes the bolus in the posterior part of the tongue to move into the pharyngeal part.
The main Aim of this stage is to prevent the food from entering the respiratory tract insted of esophagus.
Events which take place in this stage are:
Immediately after the oral stage the tongue movement causes the bolus to be pushed against the epiglottis, which closes the respiratory tract, this laryngeal opening is closed by the closure of vocal cords, The =n the upper esophageal sphicter relaxes and the blous enters the esophagus.
This stage works mainly in the opening and closing of the sphincters, now at the end of the second stage the bolus enters into the esophagus as the upper sphincter opens, after the bolus enters the sphincter closes and now a wave of peristalsis is sen initiated in the region of the upper sphincter propelling the bolus downwards which is know as ‘arboral direction’ and this movement is further helped by gravitational force. Now when the bolus has reached the lower end of the esophagus the LES relaxes and then the food enters into the stomach.