Blood Supply to Head and Neck part 2

Blood Supply to the Head and Neck - Venous Drainage

• The venous drainage of the head and neck is complex, starting from the head and neck, moving downwards.

• The superior vena cava is the end point for head and neck blood drainage, entering the right atrium of the heart. Then, it travels to the right ventricle, and the lungs for oxygenation.

• Major tributaries drain into the superior vena cava, including the right and left brachiocephalic veins.

• The brachiocephalic veins are similar to the arterial supply, the right side also including the brachiocephalic artery.

• Other key veins include the right and left internal jugular veins, right and left subclavian veins.

• The internal and external jugular veins drain blood from the brain, skull, oral cavity, and superficial structures of the face and neck.

• The external jugular vein has branches that drain the face and neck.

  • Examples of branches include the posterior retromandibular, posterior auricular, transverse cervical, suprascapular, and anterior jugular veins, and these form the external jugular vein before merging into the subclavian vein.
  • Use the pneumonic PAST: Posterior, Anterior, Suprascapular, Transverse.

• The superficial temporal vein drains the scalp.

• The maxillary vein is formed from the pterygoid venous plexus, draining the palate, nasal cavity, sinuses, and nasopharynx.

• The posterior auricular vein drains the skin behind the ears.

• The cervical and suprascapular veins drain the muscles of the neck.

• The anterior jugular vein is formed by merging superficial submandibular veins and drains the anterior part of the neck.

• The internal jugular vein has numerous tributaries, crucial for blood drainage from the face and neck.

  • Use the pneumonic MSLCP| to remember the tributaries: Middle thyroid, Superior thyroid, Lingual, Common facial, Pharyngeal, Inferior petrosal sinus.

• The inferior petrosal sinus drains parts of the brain and inner ear alongside the cochlear duct and meningeal veins.

• The common facial vein is formed by the facial and anterior retromandibular veins.

  • This vein is essential for draining blood from the forehead, eyelids, the outer portion of the nose, and the lips. Also submental area, masseter, and parotid gland, as well as the soft palate.

• The pterygoid venous plexus is a collection of small veins situated around the pterygoid muscle in the infratemporal fossa.

• The pterygoid venous plexus acts as a venous pump. It assists in returning blood to the heart during mouth opening and yawning.

• Improper inferior dental nerve blocks can cause damage to the pterygoid venous plexus causing hematoma formation.

• Knowing the blood vessels in these areas is important for identifying deviations from the norm, and avoiding complications during dental procedures.