Killian's dehiscence is a potential weak area in the posterior pharyngeal wall where a pharyngeal pouch (Zenker's diverticulum) may herniate. Between which two muscle components does this dehiscence occur?

• A Thyropharyngeus and cricopharyngeus portions of inferior constrictor ✓
• B Superior and middle constrictors
• C Middle and inferior constrictors
• D Cricopharyngeus and the esophageal circular muscle

Explanation

Killian's dehiscence lies between the oblique fibers of the thyropharyngeus (upper part of inferior pharyngeal constrictor) and the horizontal fibers of the cricopharyngeus (lower part of inferior constrictor / upper esophageal sphincter). During swallowing, increased pharyngeal pressure can force the mucosa through this anatomically weak area, forming a posterior pulsion diverticulum — Zenker's diverticulum — which typically presents in elderly patients with dysphagia and regurgitation of undigested food.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.