External carotid artery

Last revised by Joshua Yap on 26 Aug 2022

The external carotid artery (ECA) is one of the two terminal branches of the common carotid artery that has many branches that supplies the structures of the neck, face and head. The other terminal branch is the internal carotid (ICA), which is somewhat larger than the ECA, which supplies the intracranial structures.

The ECA begins at the level of the upper border of the thyroid cartilage (at the level of the fourth cervical vertebra). It takes a slightly curved course upwards and anteriorly before inclining backwards to the space behind the neck of the mandible. Along its course, it rapidly diminishes in size and as it does so, gives off various branches (see below). As it enters the parotid gland, it gives rise to its terminal branches, the superficial temporal and maxillary arteries.

The branches of the external carotid artery can be subdivided into groups:

Memorable mnemonics for these branches include:

  • Some Anatomists Like Freaking Out Poor Medical Students
  • Some American Ladies Found Our Pyramids Most Satisfactory
  • variations in origin arise from the anomalous bifurcation of the common carotid artery - bifurcations may commonly be seen at the level of the cricoid cartilage (C5 level) or at the hyoid bone (C2 level)
  • variant branching patterns
    • linguofacial trunk (incidence ~20%): common origin lingual and facial arteries
    • thyrolingual trunk (incidence ~2.5%): common origin superior thyroid and lingual arteries
    • thyrolinguofacial trunk (incidence ~2.5%): common origin superior thyroid, lingual and facial arteries
    • common occipito-auricular trunk (incidence ~12.5%): common origin occipital and posterior auricular arteries

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: head and neck arteries
    Drag here to reorder.
  • Figure 2: arteries of the neck
    Drag here to reorder.
  • Figure 3: external carotid artery (Gray's illustration)
    Drag here to reorder.
  • Figure 4: external carotid artery main branches
    Drag here to reorder.
  • Figure 5: annotated CT
    Drag here to reorder.
  • Figure 6: development from the aortic arches (Gray's illustration)
    Drag here to reorder.
  • Figure 7: carotid artery development (Gray's illustration)
    Drag here to reorder.
  • Case 1: normal ECA Doppler waveform
    Drag here to reorder.
  • Case 2: digital subtraction angiography (DSA)
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.