Killian's dehiscence (pharyngeal pouch, Zenker's diverticulum) is a herniation through a weak area in the posterior pharyngeal wall. This dehiscence is bounded by:

• A Between the superior and middle constrictors
• B Between the middle and inferior constrictors
• C Through the mucosa between the arytenoid cartilages
• D Between the oblique fibers of thyropharyngeus and the horizontal fibers of cricopharyngeus (both parts of inferior pharyngeal constrictor) ✓

Explanation

Killian's dehiscence (Killian's triangle) is the weak zone in the posterior pharyngeal wall between the oblique fibers of thyropharyngeus (upper part of inferior pharyngeal constrictor) and the horizontal fibers of cricopharyngeus (lower part, the upper esophageal sphincter). A Zenker's diverticulum forms when pharyngeal mucosa herniates posteriorly through this gap. Increased hypopharyngeal pressure during swallowing gradually pushes the mucosa through this anatomically weak point.

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

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Written and medically reviewed by the StethoPrep medical team.