EXTERNAL CAROTID ARTERY

EXTERNAL CAROTID ARTERY

Origin: External carotid artery (ECA) arises from bifurcation of common carotid artery near the upper border of thyroid cartilage.

Parts:

• Proximal part: Ascends anteriorly to hyoid bone.
• Distal part: Descends downwards and forwards to lie between the two heads of the sternocleidomastoid muscle.
• Terminal part: Divides into maxillary and superficial temporal arteries.

Course: External carotid artery passes downwards and forwards in a groove between the two heads of the sternocleidomastoid muscle and then continues to anastomose with the maxillary and superficial temporal arteries.

Relations:

• Anteriorly: Hyoid bone, superior laryngeal nerve and thyroid gland.
• Posteriorly: Sternocleidomastoid muscle.
• Medially: Lateral surface of pharynx and larynx.
• Laterally: Omohyoid muscle and internal jugular vein.

Distribution: External carotid artery supplies blood to the face, neck, ear and some parts of the head. It anastomoses with the internal carotid artery via the external carotid-internal carotid anastomosis.

FACIAL ARTERY

Origin: Facial artery arises from the external carotid artery, near the lower border of the mandible.

Course: Ascends vertically to the side of the face and divides into several branches.

Relations:

• Anteriorly: Lower lip, oral mucosa and mentalis muscle.
• Posteriorly: Buccinator muscle and mandible.

Distribution: Supplies blood to the face, lips, mouth, nose and palate.

LINGUAL ARTERY

Origin: Lingual artery arises from the external carotid artery, near the lower border of the mandible.

Course: Ascends upwards and medially to the base of the tongue.

Relations:

• Anteriorly: Oral mucosa, tongue and genioglossus muscle.
• Posteriorly: Tongue and hyoglossus muscle.

Distribution: Supplies blood to the tongue, floor of the mouth and lips.

MAXILLARY ARTERY

Origin: Maxillary artery is the terminal part of the external carotid artery, which arises near the lower border of the mandible.

Course: Passes upwards and medially through the greater palatine canal to reach the pterygopalatine fossa.

Relations:

• Anteriorly: Pterygopalatine fossa, nasal cavity and palate.
• Posteriorly: Sphenopalatine foramen, nasal cavity and palate.

Distribution: Supplies blood to the nasal cavity, palate, maxillary sinus and pharynx.

SUPERFICIAL TEMPORAL ARTERY

Origin: Superficial temporal artery arises from the external carotid artery, near the lower border of the mandible.

Course: Ascends upwards and laterally to the side of the head.

Relations:

• Anteriorly: Auricle, temporal region and skin.
• Posteriorly: Temporal region, auricle and skin.

Distribution: Supplies blood to the scalp, face and auricle.

Applied Anatomy:

• The external carotid artery is used as a landmark for locating the internal jugular vein.
• The facial artery is used for anastomosis in facial reconstruction.
• The lingual artery is used for anastomosis in tongue reconstruction.
• The maxillary artery is used for anastomosis in nasal cavity and palate reconstruction.
• The superficial temporal artery is used for anastomosis in scalp and auricle reconstruction.