Residue in the pyriform sinuses is most likely when which physiologic correlate is observed?

• A. Delayed oral transit
• B. Delayed pharyngeal transit
• C. Ineffective velopharyngeal closure
• D. Ineffective opening of the upper esophageal sphincter

Answer: (D)

Residue in the pyriform sinuses points to a bottleneck at the passage from the pharynx into the esophagus. After the pharyngeal swallow, material must pass through the upper esophageal sphincter (cricopharyngeus). This opening is enabled by coordinated hyolaryngeal elevation and relaxation of the cricopharyngeus. If the upper esophageal sphincter doesn’t open well, bolus material that reaches the pyriform sinuses can’t exit to the esophagus, so it remains as residue there. This is why the relevant physiologic correlate is ineffective opening of the upper esophageal sphincter. Delayed oral or pharyngeal transit would affect timing or clearance in different parts of the swallow, and velopharyngeal closure problems lead to nasal regurgitation rather than pyriform sinus residue.