What does the esophagus traverse at the T12 level?

The correct answer is that the esophagus traverses the esophageal hiatus at the T12 level. The esophageal hiatus is an opening in the diaphragm through which the esophagus passes as it connects the throat to the stomach. This structure is critical in maintaining the correct passage of food and is anatomically located at the T10 level, but as the esophagus descends through the diaphragm around T12, it is at this level that it also serves as a key landmark for understanding the relationship between the esophagus and other structures in the mediastinum.

While the aortic hiatus and inferior vena cava are important structures related to the diaphragm, they are associated with different pathways; the aortic hiatus primarily allows the passage of the aorta (along with the thoracic duct), and the inferior vena cava has its own hiatus at T8. The psoas muscle is not specifically traversed by the esophagus but rather runs alongside or in close proximity as the esophagus descends through the thorax into the abdomen. Understanding these anatomical relations helps clarify the pathways that structures take as they move from the thoracic cavity into the abdominal cavity.