ReviseDental would like to thank @KIKISDENTALSERVICE for the wonderful drawings in this lesson.

Arterial supply to the head

• Facial artery:
  • Origin: External carotid
  • Branches: submental a. superior and inferior labial a. lateral nasal a. angular a.
  • Note: passes superiorly over the body of there mandible at the masseter
• Superficial temporal artery:
  • Origin: External carotid
  • Branches: It is a continuation of the ex carotid a.
  • Note: terminal branch of the ex carotid a. and is in close relation to the auricular temporal nerve
• Transverse facial artery:
  • Origin: Superficial temporal a.
  • Note: exits the parotid gland
• Maxillary branch: supplies the areas missed from the above vasculature
  • Origin: External carotid a.
  • Branches: (to the face) infraorbital, buccal and inferior alveolar a.- mental a.
  • Note: Terminal branch of the ex carotid a.
• The ophthalmic branches
  • Origin: Internal carotid a.
  • Branches: Supratrochlear, supraorbital, lacrimal, anterior ethmoid, dorsal nasal
  • Note: enters orbit via the optic foramen

• Note: The face arterial supply anastomose freely.

Venous drainage of the head

• Note: follow a similar pathway to the arteries
• Superficial vessels can communicate with deep structures e.g. cavernous sinus and the pterygoid plexus. (note: relevant for spread of infection)
• Head venous vessels don't have valves

• Supratrochlear vein
  • Origin: forehead and communicates with the superficial temporal v.
  • Connects: joins with supra-orbital v.
  • Note: from the angular vein
• Supra-orbital vein
  • Origin: forehead and communicates with the superficial temporal v.
  • Connects: joins with supratrochlear v.
  • Note: from the angular vein
• Facial vein
  • Origin: angular v.
  • Receives: lateral nasal v. superior and inferior labial v.
  • Connects: pterygoid plexus
  • Note: joins with the retromandibular v. forming the common facial v.
  • Drains: internal jugular v.
• Superficial temporal vein
  • Origin: descend posterior to the zygomatic bone.
  • Connects: joins with the transverse facial v.
  • Note: forms the retromandibular v. when it unites with the maxillary v.
• Retromandibular vein
  • Origin: when the superficial temporal and maxillary v unite.
  • Note: joins with the facial v. forming the common facial v.
  • Drains: internal jugular v.

The Cavernous Sinus

Situated on the lateral body of the sphenoid bone, where it receives blood from the superior and inferior ophthalmic veins and drains into the petrosal sinuses.

Note: A common question that gets asked is: what nerves are in close relation to the cavernous sinus?

Lateral walls:

• Oculomotor n.
• Trochlear n.
• Ophthalmic n.
• Maxillary n.

Inside/ through the sinus:

• Abducens n.
• Note: internal carotid artery

The Pterygoid Plexus

Receives the veins that correspond to the maxillary artery branches. The plexus communicates with the cavernous sinus, facial v and ophthalmic v. The vessels then converge to form a maxillary vein, before draining to the retromandiblar v. and internal jugular v.

The Neck

The Common Carotid

• Right: Branch from the brachiocephalic a.
• Left: Direct branch off the aorta
• Bifurcate in the neck at level C3/ thyroid cartilage
• Carotid body (chemoreceptor) present at the bifurcation

• Internal carotid:
  • Passes within the carotid sheath
  • Carotid sinus (baroreceptor) located at the beginning of the bifurcation on the internal carotid a.
  • Anterior part of the Circle of Willis
• External carotid: (external to the carotid sheath)
  • Superior thyroid
  • Lingual
  • Facial
  • Ascending pharyngeal
  • Occipital

Note: In the head (as mentioned above) the arterial vessels that stem from the carotid are: posterior auricular, maxillary and the superficial temporal.

Note: Subclavian branches shown on the diagram below)

Venous drainage of the neck

The internal jugular vein

This vessel continues from the sigmoid sinus located in the cranial cavity. It travels within the carotid sheath and communicates with the subclavian v. forming the brachiocephalic v. at the root of the neck.

Branches that drain into the internal jugular vein are shown in the diagram below.