Head & Neck Anatomy · Vascular

Branches of External Carotid Artery

The external carotid artery supplies the face and scalp via eight named branches. Their order enables surgical navigation and haemorrhage control in the head and neck.

✦ The Mnemonic

"Students Always Learn From Outstanding Professors Mastering Surgery"

8 branches: Superior thyroid → Ascending pharyngeal → Lingual → Facial → Occipital → Posterior auricular → Maxillary → Superficial temporal

S Superior Thyroid First; descends to thyroid; external laryngeal nerve travels with it
A Ascending Pharyngeal Second; smallest; ascends between ECA and ICA
L Lingual Third; passes deep to hyoglossus; supplies tongue
F Facial Fourth; crosses mandible at anterior masseter border; palpable pulse
O Occipital Fifth; supplies posterior scalp; crosses posterior triangle
P Posterior Auricular Sixth; ascends behind ear; supplies auricle and adjacent scalp
M Maxillary Seventh; larger terminal; middle meningeal artery + inferior alveolar + sphenopalatine
S Superficial Temporal Eighth; smaller terminal; palpable anterior to tragus

📚 Clinical Breakdown

The ECA is distinguished from the ICA by: giving branches in the neck (ICA gives none in the neck) and its more anterior position. The ECA can be ligated for uncontrolled head/neck haemorrhage.

The maxillary artery (larger terminal branch) gives: middle meningeal artery (enters foramen spinosum → extradural haematoma if torn), inferior alveolar artery (lower teeth), and sphenopalatine artery (posterior nasal cavity — target in posterior epistaxis).

The superior thyroid artery accompanies the external laryngeal nerve (ELN). ELN injury during thyroid surgery causes subtle voice changes (loss of high notes; cricothyroid palsy) without complete hoarseness. Inferior thyroid artery comes from the thyrocervical trunk of the subclavian — NOT the ECA.

Terminal branches Maxillary (larger) + Superficial temporal (smaller)
Middle meningeal origin Maxillary artery → foramen spinosum
Facial pulse Anterior border of masseter at mandible
Posterior epistaxis vessel Sphenopalatine artery (maxillary branch)

⭐ Clinical Pearl

Posterior epistaxis (sphenopalatine artery) is managed with posterior nasal packing, endoscopic sphenopalatine ligation, or interventional embolisation. Significant blood can be swallowed silently — enough to cause haematemesis and haemodynamic instability before the patient appears to be bleeding severely.

← Muscles of Facial Expression