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After we have chewed food and salivary enzymes have partially digested it in our mouth, it must be
swallowed and eventually move to our stomach. To do this, it passes though the pharynx and the esophagus.
pharynx
The pharynx, often referred to as the throat, is the muscular tube behind the tongue, between the
nasal cavity and the esophagus. It is part of the digestive system as well as the respiratory system.
pharynx
esophagus
And the esophagus is the long muscular tube that carries partially digested food from the mouth to
the stomach.
Here, we’ll label and describe some of the parts in the area of the pharynx.
Nasal Cavity
The nasal cavity is the area behind the nose in which air enters and leaves the body.
Nasal Cavity
Soft Palate
Here is the soft palate. It is the back, non-bony part of the roof of the mouth.
Nasal Cavity
Soft Palate
Mouth
Here is the mouth, where food and air can enter and leave the body.
Nasal Cavity
Soft Palate
Mouth
Tongue
Here is the tongue
Nasal Cavity
Soft Palate
Mouth
Tongue
The uvula is a soft piece of flesh at the back of the soft palette.
Uvula
Nasal Cavity
Soft Palate
Uvula
Bolus (food)
Mouth
Tongue
A sample of food that has been chewed and is ready to swallow is sometimes called a
bolus.
Nasal Cavity
Soft Palate
Uvula
Bolus (food)
Mouth
Epiglottis
Tongue
The epiglottis is a flap situated just above the trachea. It is made up of elastic cartilage
tissue. When a person is not swallowing, the tip of the epiglottis points upward.
Nasal Cavity
Soft Palate
Uvula
Bolus (food)
Mouth
Epiglottis
Trachea
Tongue
The trachea is sometimes called the windpipe. It is the tube that carries air from the pharynx
to the lungs and back. It is open to the pharynx unless swallowing is taking place.
Nasal Cavity
Soft Palate
Uvula
Bolus (food)
Mouth
Epiglottis
Trachea
Tongue
Esophagus
At the bottom of the pharynx is the top of the esophagus. There is a ring of muscle surrounding the top of the
esophagus called the upper esophageal sphincter, which keeps it closed when a person is not swallowing.
Now we’ll take a closer look at what happens when we swallow some food.
As the tongue moves up it pushes the bolus back, and the uvula moves up and temporarily closes
the nasal passage. This prevents food from entering the nasal passage.
Now the bolus triggers nerves that make the trachea push upward and the epiglottis moves
downward.
The epiglottis covers the top of the trachea to prevent food from going into it,
And the top of the esophagus widens to let the bolus pass into it.
As the bolus goes down into the esophagus, the epiglottis moves back upward opening the top of the trachea
and allowing breathing again. The (click) upper esophageal sphincter contracts to re-close the top of the
esophagus.
Now, we’ll watch the whole swallowing process again…
bolus
to
stomach
esophagus
Now that the bolus has entered the esophagus, (click) it will gradually move down the esophagus
toward the stomach.
to
stomach
esophagus
The muscular walls of the esophagus contract in a wave-like manner which travels down the
esophagus and pushes the bolus toward the stomach.
A wave-like
series of
contractions in
tube walls,
which pushes
material through
a tube is called
Peristalsis
This wave-like series of contractions in tube walls, which pushes material through a tube is called Peristalsis.
Peristalsis occurs in many parts of the digestive system and is responsible for pushing partially digested food and
waste materials through the system.
Acknowledgements for Images Used
"Digestive system diagram en" by Mariana Ruiz
Villarreal(LadyofHats) - Own work. Licensed
under Public Domain via Wikimedia Commons http://commons.wikimedia.org/wiki/File:Digestiv
e_system_diagram_en.svg#mediaviewer/File:Dig
estive_system_diagram_en.svg