Cricopharyngeus Muscle (Upper Esophageal Sphincter, UES)
The cricopharyngeus is a sphincter muscle encircling the upper end of the esophagus, also called the upper esophageal sphincter or UES. It is almost always in a contracted state, even during sleep. Its action is like a continually clenched fist. This contraction closes off the entrance to the esophagus.
Whenever a person swallows, the cricopharyngeus muscle momentarily relaxes, opening its grip and allowing food or liquid to pass through and enter the esophagus.
Common Disorders
The muscle is subject to one of two disorders. Cricopharyngeal dysfunction is the failure of the muscle to relax, which causes swallowing difficulty. Cricopharyngeal spasm is hyper-contraction of the muscle, which causes a sensation of a lump in the throat but without interfering with swallowing.
Photo Examples
Cricopharyngeus muscle (1 of 4)
Cricopharyngeus muscle (1 of 4)
Opening when Contracted (2 of 4)
Opening when Contracted (2 of 4)
A distant view (3 of 4)
A distant view (3 of 4)
hypopharyngeal inlet (4 of 4)
hypopharyngeal inlet (4 of 4)
Location of the Cricopharyngeus Muscle
Cricopharyngeus Muscle (1 of 3)
Cricopharyngeus Muscle (1 of 3)
Open Cricopharyngeus Muscle (2 of 3)
Open Cricopharyngeus Muscle (2 of 3)
Closed (3 of 3)
Closed (3 of 3)
Trumpet Maneuver Reveals Cricopharyngeus Muscle
Trumpet maneuver (1 of 4)
Trumpet maneuver (1 of 4)
The “shelf” (2 of 4)
The “shelf” (2 of 4)
Cervical esophagus (3 of 4)
Cervical esophagus (3 of 4)
Closed position (4 of 4)
Closed position (4 of 4)
The Cricopharyngeus Muscle Seen During Swallowing
This person struggles to swallow due to a combination of prior tongue cancer surgery decades ago, and longterm radiation effects. Solid foods are the most problematic, and so this sequence shows an attempt to swallow water stained with blue food coloring.
Swallowing crescent (1 of 5)
Swallowing crescent (1 of 5)
Swallowing water (2 of 5)
Swallowing water (2 of 5)
Cricopharyngeus muscle (3 of 5)
Cricopharyngeus muscle (3 of 5)
Relaxed CPM (4 of 5)
Relaxed CPM (4 of 5)
Partially open esophagus due to A-CPD (5 of 5)
Partially open esophagus due to A-CPD (5 of 5)
How a Sphincter Works
Open (1 of 2)
Open (1 of 2)
Contracted (2 of 2)
Contracted (2 of 2)
Antegrade Cricopharyngeus Muscle Dysfunction, before, during, and after Myotomy
Non-relaxing cricopharyngeus muscle (1 of 4)
Non-relaxing cricopharyngeus muscle (1 of 4)
Opening the esophageal orifice (2 of 4)
Opening the esophageal orifice (2 of 4)
Laser cricopharyngeus myotomy (3 of 4)
Laser cricopharyngeus myotomy (3 of 4)
Cricopharyngeus myotomy nearly complete (4 of 4)
Cricopharyngeus myotomy nearly complete (4 of 4)
Lifting the CPM for a R-CPD Injection
These are intra-operative photos of one of nearly 2,000 persons treated for R-CPD as of December 2024. This sequence shows several things:
- The dilated, “always open” esophagus distal (below) the muscle
- How to identify the cricopharyngeus muscle
- One way of injecting the muscle.
Above the CPM (1 of 5)
Above the CPM (1 of 5)
Ridge of the CPM (2 of 5)
Ridge of the CPM (2 of 5)
Exposed CPM ( 3 of 5)
Exposed CPM ( 3 of 5)
CPM Palpated ( 4 of 5)
CPM Palpated ( 4 of 5)
Botox injection ( 5 of 5)
Botox injection ( 5 of 5)
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