Notes on Common Carotid and External Carotid Arteries

Introduction

• Overview of common carotid and external carotid arteries.
• Schematic representation of arteries and branches for better understanding.
• Mnemonics provided for easier retention.

Common Carotid Artery

• Ascends along the neck.
• Divides at the upper border of the thyroid cartilage into:
  • External Carotid Artery
  • Internal Carotid Artery
• Has no significant side branches.
• Contains chemoreceptors called carotid bodies (senses chemical changes in blood).
• Contains carotid sinus (senses stretch and changes diameter of blood vessels).

External Carotid Artery

• Ascends and divides into two terminal branches at retromandibular fossa:
  • Maxillary Artery
  • Superficial Temporal Artery
• Side branches categorized by location (cervical and facial).

Side Branches of External Carotid

• Mnemonic: Some Anatomists Like Freaking Out Poor Medical Students

Anterior Branches:

1. Superior Thyroid Artery
   • Origin: Level of hyoid bone.
   • Supplies thyroid cartilage and neck muscles:
     • Muscular branches: thyrohyoid, sternohyoid, omohyoid.
     • Supplies middle region of sternocleidomastoid.
     • Superior Laryngeal Artery (supplies larynx).
2. Ascending Pharyngeal Artery
   • Only medial branch.
   • Supplies pharynx, pharyngeal constrictor muscles, and meninges.
   • Gives off Inferior Tympanic Artery (supplies middle ear).
3. Lingual Artery
   • Origin: Level of thyroid bone.
   • Supplies tongue:
     • Gives off dorsolingual and sublingual arteries.
4. Facial Artery
   • Origin: Mandibular angle.
   • Travels to face and becomes Angular Artery (medial side of eye).

Cervical Branches:

• Mnemonic: Tags All

1. Tonsillary Artery (supplies palatine tonsil).
2. Ascending Palatine Artery (supplies soft palate).
3. Glandular Artery (supplies submandibular glands).
4. Submental Artery (supplies submandibular gland and floor of mouth).

Facial Branches:

1. Angular Artery (terminal branch; communicates with dorsal nasal artery from ophthalmic artery).
2. Superior Labial Artery (supplies upper lip).
3. Inferior Labial Artery (supplies lower lip).
4. Lateral Nasal Artery (supplies nasal dorsum and wing).

Posterior Branches:

1. Occipital Artery
   • Supplies occipital region.
   • Has mastoid and sternocleidomastoid branches.
2. Posterior Auricular Artery
   • Supplies scalp behind ear and external ear.
   • Has Stylomastoid Artery (supplies middle and internal ear).

Terminal Branches

1. Maxillary Artery
   • Origin: Behind the neck of the mandible.
   • Divided into three parts:
     1. Branches from Temporomandibular Joint:
        • Deep Auricular Artery (supplies external acoustic meatus and tympanic membrane).
        • Anterior Tympanic Artery (supplies middle ear).
        • Middle Meningeal Artery (risk for epidural hematoma).
        • Inferior Alveolar Artery (supplies lower teeth, gums, and floor of mouth).
     2. Branches from Infratemporal Fossa:
        • Supplies muscles of mastication (mesoteric, deep temporal, pterygoid, and buccal arteries).
     3. Branches from Pterygopalatine Fossa:
        • Superior Posterior Alveolar Artery (supplies upper molars).
        • Infraorbital Artery (supplies anterior face region).
        • Descending Palatine Artery (supplies hard and soft palate).
   • Sphenopalatine Artery (anastomoses at nasal septum; associated with nosebleeds).
2. Superficial Temporal Artery
   • Divides into frontal and parietal branches.
   • Supplies forehead and lateral side of head.
   • Side branches: anterior auricular branch, transverse facial artery, and middle temporal artery.

Conclusion

• Importance of reviewing material multiple times for retention.
• Hope this information clarifies the structure and function of the common and external carotid arteries.