The oesophagus, or esophagus, has three significant narrowings along its length where it is constricted. These constrictions are clinically important because they are common sites for the lodgement of swallowed foreign objects or the impaction of food boluses.
The Three Oesophageal Narrowings:
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Cervical Constriction (Cricoid Constriction):
- Location: This is the narrowest point of the oesophagus and is located at its beginning, where it connects to the pharynx. Specifically, it lies at the level of the cricoid cartilage.
- Vertebral Level: Approximately at the level of the C5/C6 vertebrae.
- Cause: Due to the cricoid cartilage of the larynx.
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Thoracic Constriction (Aortic Constriction):
- Location: This constriction occurs in the superior mediastinum where the oesophagus is crossed by the aortic arch.
- Vertebral Level: Approximately at the level of the T4/T5 vertebrae.
- Cause: Due to the compression from the arch of the aorta.
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Abdominal Constriction (Diaphragmatic Constriction):
- Location: This narrowing is found where the oesophagus passes through the diaphragm via the esophageal hiatus.
- Vertebral Level: Approximately at the level of the T10/T11 vertebrae.
- Cause: Due to the muscular fibers of the diaphragm constricting the oesophagus as it passes through.
In summary, the three narrowings of the esophagus are the cervical constriction, caused by the cricoid cartilage; the thoracic constriction, caused by the aortic arch; and the abdominal constriction, caused by the esophageal hiatus of the diaphragm.
