esophagus

Gag Reflex – Episode 115

 in Podcasts  tagged esophagus / gag reflex / hypersensitive / larynx / pharynx / reflux / swallow / vomit by

A cartoon image of a white male with short brown hair, in a blue, long-sleeved collared shirt and reck necktie, with his face tipped upward. He is holding a coffee pot at arm's length above his face and pouring coffee straight down his throat. Your gag reflex protects you from things improperly entering your throat, airway, and esophagus - whether it is a liquid like coffee or something solid like a sword.

Gag Reflex Basics

The official name of your gag reflex is the pharyngeal reflex or laryngeal spasm.  Trigger points for the gag reflex can be found on the roof of the mouth, back of the tongue, in the tonsil area, the uvula, and the back of the throat.  The purpose of this reflex is to prevent objects from entering the throat that did not first progress through the normal swallowing process.  It also helps prevent choking.

Gag Reflex Progress

When the reflex is triggered, the soft palate raises to close off the nasal passage.  Then the pharyngeal muscles contract on both sides to try and force whatever made it too far down back up into the mouth.  If the input is strong enough, it can also trigger vomiting (this is how vomiting is induced in eating disorders such a bulimia).

Do you Gag?

One in three people lacks a gag reflex, which means rather large things can enter their throats without triggering a reflex.  This is possibly how sword-swallowing got its start.

The other side of this coin is someone with a hypersensitive gag.  They can have trouble swallowing large pills and large bites of food.  Dentist visits and even neckties can trigger this unpleasant reflex.  It can be a part of a larger issue, such as Sensory Processing Disorder or Autism.  Or it can be a preconditioned issue due to a previous experience.  In either case, speech or occupational therapy can be done and will include desensitizing areas of the mouth to touch.

Other Protective Reflexes

  1. The Reflexive Pharyngeal Swallow is a triggered swallow that clears the pharynx of residue.  The glottis will close and allow the pharynx to move stuff to the digestive tract.  This is a protective mechanism to keep stuff out of the airways.
  2. Phayngoglottal Closure Reflex happens when the glottis closes inside the larynx without the continuation of a swallow.
  3. Phango-Upper Esophageal Sphincter Contractile Reflex occurs during any type of reflux from the stomach.  While some stomach contents may make it past the lower esophageal sphincter, so the upper one prevents it reaching into the throat and mouth.

Bottom Line

All of these reflexes are protective to prevent choking or improper ingesting of things.  They can be damaged to different degrees during head trauma or stroke.  But surprisingly, smoking causes the most damage to the protective reflexes on the pharynx.

Callbacks

Swallowing

Mouth Parts

Connect with me

Support us on Patreon

Give us your Feedback

Join the Pharmacist Answers Podcast Community on Facebook

Subscribe: iTunes, Stitcher, GooglePlay, TuneIn Radio

Like the Facebook page

Music Credits: Up In My Jam (All Of A Sudden) by – Kubbi https://soundcloud.com/kubbiCreative Commons — Attribution-ShareAlike 3.0 Unported— CC BY-SA 3.0 http://creativecommons.org/licenses/b…Music provided by Audio Library https://youtu.be/tDexBj46oNI

Swallowing – Episode 112

 in Podcasts  tagged dentist / esophagus / food / mouth / reflex / saliva / Sleep / swallowing / teeth / throat / tongue by

 

A young child with no shirt and light brown hair against a blue sky is swallowing gulps of orange juice from a clear plastic bottle.

The 3 Phases of Swallowing

Oral Phase

This phase includes chewing and saliva mixing with the food to form a bolus (a little glob of mashed up food). Then the tongue moves the bolus towards the back of the mouth.  The tongue starts by pressing against the hard palate behind the front teeth.  Then the sides of the tongue raise up to also press against the hard palate inside the teeth.  At this point, the bolus has nowhere to go except towards the back of the throat.

Pharyngeal Phase

The vocal folds in the larynx close to keep food out. The larynx also moves up as the epiglottis covers it to seal off the airway. Then the soft palate and uvula move up and close off the nasal passage  So now there is only one way out.

Esophageal Phase

The bolus moves into the esophagus (because it is the only open path). The esophageal muscles contract from top to bottom (this waving, rhythmic muscle movement is called peristalsis) to push the bolus into the stomach.

Swallowing Reflex

There are sensory receptors in the pharynx and tongue that receive touch signals.  When they are touched by a bolus, the signals are sent to the brain stem and the return signal results in involuntary and automatic movements of the larynx and epiglottis.  This is a good thing since swallowing is a very rhythmic process and you want food and drink to continue going in the correct direction.

This reflex cannot be triggered by sticking your finger in your throat.  You are more likely to trigger a gag reflex that way.  The voluntary steps of swallowing must be initiated before the involuntary portion of the process takes over.

Weird Swallowing Scenarios

How do you swallow with your mouth open?

At the dentist, you are usually laying in the chair on your back and facing the ceiling.  There are at least three tools and two hands in your mouth.  Things in your mouth trigger saliva production.  Also, generally one of the tools the dentist is using is emitting water.  The natural reflex when you have to hold your mouth open for a long time is to bring the back of the tongue and the soft palate together.  This seals off the throat and allows you to still breathe through your nose.  The liquid in your mouth plus gravity creates a puddle at the seal of your tongue and soft palate.  Because the touch sensors to trigger your swallowing reflex are also in this area, it is likely you begin to panic because if they don’t hurry and use the suctioning straw to remove the liquid, you’re going to swallow!

Do you swallow in your sleep?

A study was done to find that the only times you swallow while sleeping is during arousal and during REM.  My logical deduction regarding why is that when you’re aroused or in one of the more shallow phases of sleep, that is when you can voluntarily move – roll over, adjust the bedding, and swallow.  During REM sleep, most people will experience sleep paralysis, so whatever exciting things are happening in their brain, the body is not likely to act it out.  Because the brain cannot tell if a dream is real or imaginary, the feeling solicited can trigger hormones secretions and saliva production. Increased saliva, just like in the dentist scenario, can trigger swallowing.

Connect with me

Support us on Patreon

Give us your Feedback

Join the Pharmacist Answers Podcast Community on Facebook

Subscribe: iTunes, Stitcher, GooglePlay, TuneIn Radio

Like the Facebook page

Music Credits: Up In My Jam (All Of A Sudden) by – Kubbi https://soundcloud.com/kubbiCreative Commons — Attribution-ShareAlike 3.0 Unported— CC BY-SA 3.0 http://creativecommons.org/licenses/b…Music provided by Audio Library https://youtu.be/tDexBj46oNI