circular fibres
Last reviewed 01/2018
The circular fibres of the oesophagus are within the longitudinal muscle fibre layer. They from a continuous sheath around the oesophagus.
Superoposteriorly, they merge with the inferior constrictors, particularly cricopharyngeus, of the pharynx. Superoanteriorly, they merge with the tendon of the longitudinal muscle that inserts into the posterior surface of the lamina of the cricoid cartilage. Inferiorly, the circular muscle fibres merge with the oblique fibres of the gastric wall.