External Carotid Artery and its Branches

Overview

• External Carotid Artery: One of the two main divisions of the common carotid artery.
• Origin: Aortic arch on the left, brachiocephalic trunk on the right.
• Pathway: Ascends the lateral neck within the carotid sheath behind the sternocleidomastoid muscle.
• Function: Supplies external structures of the head and face.

Key Facts

• Source: Common carotid artery at the thyroid cartilage level in the larynx.
• Mnemonic for Branches: Some Anatomists Like Freaking Out Poor Medical Students (Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior auricular, Maxillary, Superficial temporal).

Borders and Relations

• Medially: Hyoid bone, pharynx wall, superior laryngeal nerve, parotid gland.
• Laterally: Internal carotid artery, superior laryngeal nerve.
• Posterosuperiorly: Styloglossus muscle, stylopharyngeus muscle, glossopharyngeal nerve, vagus nerve's pharyngeal branch, parotid gland.
• Anteriorly: Skin, superficial fascia, platysma, deep cervical fascia, sternocleidomastoid muscle.

Branches

Superior Thyroid Artery

• Origin: Level of hyoid bone.
• Course: Descends along the thyrohyoid muscle's lateral border to thyroid gland apex.
• Branches: Superior laryngeal, sternocleidomastoid, cricothyroid, infrahyoid, glandular branches.
• Mnemonic: I Shall Squeeze Charlie's Glutes (Infrahyoid, Superior laryngeal, Sternocleidomastoid, Cricothyroid, Glandular).

Ascending Pharyngeal Artery

• Smallest branch.
• Course: From medial surface to base of the cranium.
• Supplies: Pharynx, soft palate, ear, meninges, neck muscles, sympathetic trunk, and several nerves.

Lingual Artery

• Origin: Anteromedial aspect at the hyoid bone level.
• Course: Forms three parts relative to hyoglossus muscle.
• Supplies: Tongue and floor of the mouth.

Facial Artery

• Course: Emerges above lingual artery, travels anterosuperiorly, deep to muscles, curves around mandible.
• Supplies: Face structures, soft palate, palatine tonsil, auditory tube, submandibular gland.

Occipital Artery

• Origin: Posterior aspect.
• Course: Deep to digastric muscle, traverses occipital groove.
• Supplies: Neck muscles, meninges, ear pinna, mastoid air cells.

Posterior Auricular Artery

• Course: Ascends in neck, travels between auricular cartilage and mastoid process.
• Supplies: Neck muscles, parotid gland, external ear structures, facial nerve.

Maxillary Artery

• Larger terminal branch.
• Course: Passes anteriorly, enters infratemporal fossa.
• Supplies: Jaw, teeth, muscles of mastication, ears, nose.

Superficial Temporal Artery

• Smaller terminal branch.
• Course: Ascends from parotid gland, divides into frontal and parietal branches.
• Supplies: Face and scalp.

Clinical Relevance

• Carotid Artery Disease: Buildup of plaques that can lead to ischemia or clot formation.
  • Prevention: Healthy diet, physical activity, stress management.

Sources

• Kenhub article reviewed by medical experts.
• Additional references include Radiopaedia and Atlas of Human Anatomy.