What are the major landmarks for the cricopharyngeus muscle?

Anatomical Landmarks of the Cricopharyngeus Muscle

The cricopharyngeus muscle is located at the pharyngoesophageal junction, extending from the lateral aspects of the cricoid cartilage posteriorly to form a horizontal band at the level of the C5-C6 vertebrae, positioned between the inferior pharyngeal constrictor muscle superiorly and the cervical esophagus inferiorly. 1, 2

Primary Anatomical Relationships

Skeletal Landmarks

• Cricoid cartilage: The cricopharyngeus originates from the lateral aspects of the cricoid cartilage and forms a horizontal muscular band posteriorly 1, 3
• Vertebral level: Located at approximately the C5-C6 vertebral level, marking the transition from pharynx to esophagus 3

Adjacent Muscular Structures

• Superior boundary: The inferior pharyngeal constrictor muscle lies immediately above the cricopharyngeus 3
• Inferior boundary: The cervical esophagus begins immediately below the cricopharyngeus 3
• Functional unit: The cricopharyngeus forms the most important component of the upper esophageal sphincter (UES), with contributions from the inferior pharyngeal constrictor above and cervical esophagus below 3

Neural Landmarks

• Recurrent laryngeal nerve (RLN): The RLN provides motor innervation to the cricopharyngeus muscle, along with the inferior constrictor and all intrinsic laryngeal muscles except the cricothyroid 4
• Tracheoesophageal groove: The RLN courses through this groove in close proximity to the cricopharyngeus 4

Manometric vs. Anatomic Considerations

A critical pitfall: The anatomic location of the cricopharyngeus muscle does not correspond precisely to the entire manometric high-pressure zone of the UES 2

• The cricopharyngeus corresponds to the distal one-third of the sphincteric high-pressure zone 2
• The peak high-pressure zone is located proximal to the anatomic cricopharyngeus muscle 2
• This discrepancy is clinically important when planning interventions such as myotomy or botulinum toxin injection 2

Surgical Identification

During thyroid surgery, the cricopharyngeus can be identified by:

• Its relationship to the tracheoesophageal groove where the RLN travels 4
• Its position posterior to the thyroid gland and adjacent to the esophagus 4
• Recognition that the RLN innervates this muscle, making nerve preservation critical to maintaining cricopharyngeal function 4, 5