There are even those in the eyes that regulate the flow of light.
Some sphincters are as large as a walnut, while others are microscopic.
It also explains what can happen if they don’t work.
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The UES protects the entrance to theesophagus, which carries food from your throat to your stomach.
The swallowing reflex triggers the opening of this sphincter.
The UES prevents air from getting into the esophagus while you breathe.
It also prevents you from breathing food into your lungs.
Because of its location, the UES also plays a role in burping and vomiting.
(The termcardiacin this context does not refer to the heart.)
It also prevents stomach acid from washing back up into the esophagus.
A malfunction of the LES is one of the primarycauses of GERD.
The SO ensures that the right amounts are released when food passes into the duodenum.
Sphincter of Oddi dysfunction (SOD)is a condition where this SO doesn’t work as it should.
This causes bile and pancreatic enzymes to back up into the stomach.
A relatively rare disorder, SOD can cause waves of stomach pain along with severe chest pain.
Also known as theileocecalvalve, not much is known about this sphincter.
The anal sphincter regulates defecation (the evacuation of stool from the body).
The inner muscle has involuntary control, and the outer muscle has voluntary control.
Dysfunction of the urethral sphincter can lead tourinary incontinence(the loss of bladder control).
Precapillary Sphincters
Precapillary sphinctersare the most numerous punch in of sphincter in the human body.
These involuntary sphincters regulate the flow of blood into the tiniest blood vessels in the body, calledcapillaries.
The same can occur if the iris dilator muscles malfunction, causingmydriasis(abnormally large pupils).
Summary
Sphincters are circular muscles that open and close passages in the body.
There are sphincters in other parts of the body as well.
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