Oesophageal hiatus

Hiatus oesophageus

MuscularDeep musclesThorax

View in 3D

What it is
Oval opening in the muscular part of the diaphragm at about T10, formed by a sling of right-crus fibres, transmitting the oesophagus and the vagal trunks.
Function
Its muscular sling acts as an external lower oesophageal sphincter, helping to prevent acid reflux.
Size
About 2.5 × 1.5 cm.
Clinical note
Widening of the hiatus lets the top of the stomach slide into the chest — a sliding hiatus hernia, a common cause of heartburn.

Nearby muscular structures Aortic hiatus (median arcuate ligament), Caval opening of the diaphragm, Central tendon of the diaphragm, Infraspinatus, Pectoralis major, Pectoralis minor, Rhomboid major, Serratus anterior, Subscapularis, Teres major