What is the process of swallowing?

The process of swallowing, also known as deglutition, is a complex physiological process that involves the coordination of several muscles and nerves to move food from the mouth to the stomach. It is divided into three phases:

1. Oral Phase:

- This is the voluntary stage of swallowing initiated when you decide to swallow.

- The tongue presses the food against the roof of the mouth and forms a bolus (a rounded mass of food).

- Saliva is mixed with the food, lubricating it and beginning the chemical breakdown of carbohydrates.

2. Pharyngeal Phase:

- This phase is involuntary and begins as the bolus moves to the back of the throat.

- The soft palate elevates, closing off the nasal cavity to prevent food from entering the nose.

- The epiglottis, a small flap of tissue, folds down to cover the opening of the windpipe, preventing food from entering the lungs.

- Powerful pharyngeal muscles contract, propelling the bolus downward into the esophagus.

3. Esophageal Phase:

- This phase is also involuntary and involves the movement of the bolus through the esophagus, a muscular tube connecting the throat to the stomach.

- Peristaltic waves, rhythmic contractions of the esophageal muscles, push the bolus downward.

- The lower esophageal sphincter, a muscular ring at the junction of the esophagus and stomach, relaxes to allow the bolus to enter the stomach.

The entire process of swallowing usually takes a few seconds and happens automatically without much conscious effort. However, swallowing difficulties (dysphagia) can occur due to various conditions affecting any of these phases, leading to problems with eating and drinking.