Lecture Notes: Common Carotid and External Carotid Arteries

Overview

• Common Carotid Artery

  • Ascends along the neck.
  • Divides into external and internal carotid arteries at the upper border of the thyroid cartilage.
  • Contains chemoreceptors called carotid bodies for sensing bloodstream chemical changes.

• External Carotid Artery

  • Continues upwards through the retromandibular fossa.
  • Divides into maxillary artery and superficial temporal artery.

Mnemonics

• For external carotid branches: "Some Anatomists Like Freaking Out Poor Medical Students."
• For facial artery branches: "Tags All."

Branches of the External Carotid Artery

Anterior Branches

• Superior Thyroid Artery

  • Descends to thyroid cartilage, supplies superior side.
  • Gives off branches to neck muscles, sternocleidomastoid, and larynx.

• Ascending Pharyngeal Artery

  • Only medial branch.
  • Supplies pharynx and posterior cranial cavity.
  • Gives off inferior tympanic artery (middle ear).

• Lingual Artery

  • Supplies the tongue.
  • Branches: dorsolingual and sublingual arteries.

• Facial Artery

  • Branches out at mandibular angle.
  • Cervical branches: tonsillary artery, ascending palatine, glandular artery.
  • Facial branches: angular artery, superior/inferior labial artery, lateral nasal.

Posterior Branches

• Occipital Artery

  • Supplies occipital region.
  • Branches: mastoid, sternocleidomastoid, external ear, neck muscles.

• Posterior Auricular Artery

  • Supplies scalp and external ear.
  • Branches: stylomastoid artery (middle ear).

Terminal Branches

Maxillary Artery

• Origins: Behind neck of the mandible.
• Divisions:
  • First part: behind temporomandibular joint.
  • Second part: infratemporal fossa.
  • Last part: pterygopalatine fossa.
• Key Branches:
  • Deep auricular, anterior tympanic, middle meningeal, inferior alveolar.
  • Infratemporal fossa branches: mesoteric, deep temporal, pterygoid, buccal.
  • Pterygopalatine fossa branches: superior posterior alveolar, infraorbital, descending palatine, sphenopalatine.

Superficial Temporal Artery

• Divides: Frontal and parietal branches.
  • Frontal branch supplies forehead.
  • Parietal branch supplies side of the head and communicates with other parietal.
• Side Branches: Anterior auricular, transverse facial, middle temporal.

Important Points

• Middle Meningeal Artery: Vital due to its role in potential epidural hematoma from skull trauma.
• Key Connections: Anastomoses at Little's/Kisselbach's area (common nosebleeds).

Conclusion

• The external carotid artery has numerous branches supplying various regions of the face, head, and neck. Each branch has specific supply regions, which can be remembered using provided mnemonics.
• Repeated review helps in memorization of the anatomy of these arteries.