1
Q
A ring
A
The muscular ring above the vestibule.
2
Q
B ring
A
The mucosal ring below the vestibule.
This is a thin constriction at the GE junction.
Symptomatic dysphagia can occur if it narrows (historically defined at < 13 mm in diameter). If it’s narrowed (and symptomatic) you call it a Schatzki.
3
Q
Z Line:
A
Represents the squamocolumnar junction (boundary between esophageal and gastric epithelium).
This doesn’t necessarily correspond with the B-ring.
Endoscopy finding, and is only rarely seen as a thin serrated line.
4
Q
A
