Aortic isthmus

The aortic isthmus is the part of the aorta just distal to the origin of the left subclavian artery at the site of the ductus arteriosus.

This portion of the aorta is partly constricted in the fetus because of the lack of flow within the aortic sac and ascending aorta. It marks the partial separation of fetal blood flow derived from the right and left ventricles.

History and etymology

Derived from the Ancient Greek ισθμος (isthmos) meaning a neck of land 3.

Related pathology

Anatomy: Thoracic
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Article information

rID: 22291
Section: Anatomy
Synonyms or Alternate Spellings:
  • Isthmus of the aorta
  • Aortic isthmi

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Cases and figures

  • Figure 1: thoracic aorta
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