Esophageal Sphincter, Upper |
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| Cricopharyngeus Muscle; Cricopharyngeus Muscles; Muscle, Cricopharyngeus; Muscles, Cricopharyngeus; Sphincter, Upper Esophageal | |
| The structure at the pharyngoesophageal junction consisting chiefly of the cricopharyngeus muscle. It normally occludes the lumen of the ESOPHAGUS, except during SWALLOWING. | |