20210815 : Swallowing

Every afternoon I struggle. I am fed some fluid (juice or soup or just warm water) orally. They give it in a small spoon, not full, just half spoons. It may be about 3-4ml each time. However, I am unable to swallow it. It invariably goes into the wind pipe, causing a violent cough and struggle and most days I am unable to withstand it and we stop after a few spoons.

For an effective swallow,

1. The morsel of anything (called bolus) needs to be encapsulated and pushed back and down into the throat (pharynx)

2. At the same time, the nasal cavity is closed off to prevent stuff from going into the nose.

3. As the bolus comes down, the lungs have to hold the breath and vocal folds (or vocal chords) needs to close so as to close the wind pipe.

4. The epiglottis (another soft tongue like muscle) seals off the wind pipe fully.

5, the entrance to the food pipe (circular muscles called sphincter in the upper oesophageal cavity) needs to open up to allow the bolus to get in.

6. At this time, the larynx (or voice box, sometimes referred to as Adam's Apple) needs to elevate and basically get out of the way to open the oesophagus fully)

7. Once the bolus goes in, the muscles at the top needs to squeeze to start the movement down the food pipe (peristalsis)

That is what it takes, in layman's terms. The actual process is even more complex and I have simplified it.

That's not all. The lower end of the oesophagus (entrance to stomach) has another sphincter muscle which has to close tight to prevent any back flow. Otherwise we can kiss goodbye to a restful nap after a heavy meal.

That doesn't sound like swallowing food. It sounds like a rocket launch.

A rocket launch has several seconds of countdown. The swallow through the throat (pharyngeal cavity) happens in a fraction of a second and everything needs to be coordinated and sequenced correctly.

If something goes wrong and the food bits enter the wind pipe, involuntary defenses of cough reflex kicks in for protection.

Most of it is involuntary and subconscious. We weren't trained for it or practiced it before the game. Babies do it on day 1. Not just us, every animal does it. 

And it's still a very small part of everything we do everyday without having to think about it.

And we still look for other miracles...