External Carotid Artery

Common carotid artery and branches of the external carotid artery - Color Atlas of Human Anatomy Vol. 2

Origin and Course

The external carotid artery (ECA) is one of the two terminal branches of the common carotid artery, arising at the carotid bifurcation (typically at the level of the superior border of the thyroid cartilage, around C3-C4 vertebral level). At its origin it lies anteromedial to the internal carotid artery, but as it ascends it rotates laterally.

The ECA enters the inferior border of the parotid gland (or passes deep to it), gives off the posterior auricular artery, and then divides into its two terminal branches - the maxillary artery and the superficial temporal artery - near the lower border of the ear. - Gray's Anatomy for Students

Distinguishing ECA from ICA

A key clinical landmark: the hypoglossal nerve (CN XII) lies directly upon the external carotid artery, which helps distinguish the ECA from the internal carotid artery before ligation. The ICA has no branches in the neck, while the ECA gives off multiple branches from the outset. - K.J. Lee's Essential Otolaryngology

Branches - The "SALFOPMS" Mnemonic

The ECA gives off 8 branches in total (3 anterior, 2 medial/posterior, 2 terminal, 1 posterior):

Anterior Branches

Branch	Supplies
Superior thyroid artery (1st)	Thyrohyoid muscle, laryngeal structures, sternocleidomastoid, cricothyroid, thyroid gland
Lingual artery (2nd anterior)	Tongue muscles, palatine tonsil, soft palate, epiglottis, floor of mouth, sublingual gland
Facial artery (3rd anterior)	Face from mandible inferior border to medial canthus, soft palate, palatine tonsil, pharyngotympanic tube, submandibular gland

The superior thyroid artery arises near or at the bifurcation, passes downward and forward to the superior pole of the thyroid.
The lingual artery arises at the level of the hyoid bone, passes deep to CN XII, between the middle constrictor and hyoglossus.
The facial artery passes deep to stylohyoid and the posterior belly of digastric, loops through/around the submandibular gland, and crosses the mandible just anterior to the masseter muscle to enter the face.

Medial Branch

Branch	Supplies
Ascending pharyngeal artery	Pharyngeal constrictors, stylopharyngeus, palate, palatine tonsil, pharyngotympanic tube, posterior cranial fossa meninges

The smallest branch; arises from the posterior aspect of the ECA and ascends between the ICA and pharynx.

Posterior Branches

Branch	Supplies
Occipital artery	Sternocleidomastoid, posterior cranial fossa meninges, mastoid cells, deep back muscles, posterior scalp
Posterior auricular artery	Parotid gland, nearby muscles, external ear and scalp posterior to the ear, middle and inner ear structures

The occipital artery arises near the level of the facial artery origin, passes upward and posteriorly deep to the posterior belly of digastric, and emerges on the posterior scalp.
The posterior auricular artery is a small branch that ascends posterosuperiorly.

Terminal Branches

Branch	Supplies
Superficial temporal artery	Parotid gland and duct, masseter, lateral face, anterior ear, temporalis muscle, parietal and temporal scalp regions
Maxillary artery	Extensive - external acoustic meatus, tympanic membrane, TMJ, dura mater, meninges, mandibular teeth and skin, infratemporal fossa structures, maxillary sinus, upper teeth and gingivae, infra-orbital skin, palate, pharyngeal roof, nasal cavity

The superficial temporal artery appears as the upward continuation of the ECA, emerges from the upper border of the parotid gland giving off the transverse facial artery.
The maxillary artery is the larger terminal branch; it passes deep to the neck of the mandible into the infratemporal fossa and on into the pterygopalatine fossa.
Gray's Anatomy for Students, Table 8.13

Clinical Significance

Nasal Blood Supply (Epistaxis)

The ECA supplies the nasal cavity via its facial and maxillary branches:

The facial artery supplies the anterior septum (nasal septal rami of superior labial artery), vestibule (lateral nasal artery), and a small nasal cavity area.
The maxillary artery provides the most important supply via the sphenopalatine and greater palatine branches:
- The sphenopalatine artery enters through the sphenopalatine foramen, dividing into posterior septal and posterior lateral rami - it is the most important nasal cavity supply overall.
- The greater palatine artery supplies the anteroinferior nasal floor and septum, with terminal branches anastomosing in Little's area.
Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 1

Scalp Supply

Three ECA branches supply the majority of the scalp - the superficial temporal, posterior auricular, and occipital arteries supply the lateral and posterior aspects. - Gray's Anatomy for Students

Facial Blood Supply

The blood supply of the face is almost entirely from ECA branches. The facial artery (just posterior and medial to the angle of the mandible) is the primary supply; the ECA system also supplies the largest area of the forehead via the superficial temporal artery. - Fitzpatrick's Dermatology

ECA Ligation

Prior to ligation of the ECA (e.g. for control of hemorrhage), identification of its first few branches is essential to confirm it is not the ICA (the ICA gives no neck branches). The relationship of the hypoglossal nerve is also a key landmark. - K.J. Lee's Essential Otolaryngology

Surgical Relevance (Penetrating Vascular Injury)

In proximal internal carotid artery injuries, the ECA can be transposed to obtain inflow to the native ICA - demonstrating the important collateral and reconstructive role of the ECA in carotid surgery. - Mulholland & Greenfield's Surgery, 7e

Summary Table

Group	Branch	Mnemonic letter
Anterior	Superior thyroid	S
Medial	Ascending pharyngeal	A
Anterior	Lingual	L
Anterior	Facial	F
Posterior	Occipital	O
Posterior	Posterior auricular	P
Terminal	Maxillary	M
Terminal	Superficial temporal	S

A common mnemonic is "Some Angry Lady Figured Out PMS" - Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior auricular, Maxillary, Superficial temporal.

Create a detailed anatomy poster of ECA branches

Generating Image

Detailed medical anatomy education poster of the External Carotid Artery (ECA) and all its branches, labeled diagram on a clean white background. Show a lateral view of the human head and neck with the skull outline visible. Draw the common carotid artery bifurcating into the internal carotid artery (ICA) and external carotid artery (ECA) at the level of the thyroid cartilage. Show all 8 branches of the ECA with clear labeled arrows: ANTERIOR BRANCHES (labeled on the left side): 1. Superior Thyroid Artery - first branch, descending to thyroid gland 2. Lingual Artery - at hyoid bone level, going to tongue 3. Facial Artery - crossing mandible anterior to masseter, winding up to medial canthus of eye MEDIAL BRANCH: 4. Ascending Pharyngeal Artery - smallest branch, ascending between ICA and pharynx POSTERIOR BRANCHES: 5. Occipital Artery - passing deep to digastric, supplying posterior scalp 6. Posterior Auricular Artery - going to posterior ear and scalp TERMINAL BRANCHES (labeled at top): 7. Superficial Temporal Artery - ascending over temporal region to scalp 8. Maxillary Artery - passing deep to mandible neck into infratemporal fossa Include a small inset box listing the mnemonic: "Some Angry Lady Figured Out PMS" with each letter mapped to the branch name. Include a second inset showing the carotid bifurcation close-up with ICA having no branches and ECA having multiple branches. Color arteries in red. Add a title at top: "EXTERNAL CAROTID ARTERY - Branches & Distribution". Include small icons or annotations showing what each branch supplies. Professional medical textbook illustration style.

External Carotid Artery - Branches & Distribution

Here is your detailed ECA anatomy poster! It includes:

Lateral skull/neck view showing the common carotid bifurcation into ICA and ECA
All 8 named branches labeled with arrows in their correct anatomical positions
Grouping by anterior, medial, posterior, and terminal branches
The "Some Angry Lady Figured Out PMS" mnemonic inset
Color-coded arteries in red with supply annotations
A bifurcation close-up inset highlighting that the ICA has no branches in the neck (key clinical distinguishing feature)

The branches in order from the mnemonic:

Letter	Branch
S	Superior thyroid
A	Ascending pharyngeal
L	Lingual
F	Facial
O	Occipital
P	Posterior auricular
M	Maxillary
S	Superficial temporal

This is a shared conversation. Sign in to Orris to start your own chat.