HEAD AND NECK: VENOUS DRAINAGE

• Veins of the head and neck may be divided into:

  • Veins of the brain, venous sinuses, diploic veins, and emissary veins
  • Veins of the scalp, face, and neck
• Veins of the Brain:

  • thin walled
  • have no valves
• Veins of the brain consist of the following:

  • Cerebral veins
  • Cerebellar veins
  • Veins of the brainstem
• Veins of the brain all drain into the neighboring venous sinuses.
• Venous sinuses are situated between the periosteal and the meningeal layer of the dura mater.
• Venous sinuses have thick, fibrous walls. However, they don't possess valves.
• There are 6 venous sinuses.

  • Superior Sagittal Sinus
  • Inferior Sagittal Sinus
  • Straight Sinus
  • Right Transverse Sinus
  • Left Transverse Sinus
  • Sigmoid Sinus
• Superior Sagittal Sinus is found at the upper Falx cerebri while the Inferior Sagittal Sinus can be found at the lower Falx cerebri.
• Straight Sinus is at the junction of Falx cerebri and the Tentorium cerebelli. It is formed by the union of Inferior Sagittal Sinus and Great Cerebral Vein.
• Right Transverse Sinus comes from the Superior Sagittal Sinus while Left Transverse comes from the Straight Sinus.
• Sigmoid Sinus is from the Transverse Sinuses going to the Internal Jugular Vein.
• Diploic veins occupy channels within the bones of the vault of the skull.
• Emissary Veins:

  • They are valveless and pass through the skull bones.
  • They connect the veins of the scalp to the venous sinuses.
• Emissary veins are an important route for the spread of infection.
• Facial vein is formed at the medial angle of the eye by the union of the supraorbital and supratrochlear veins. It is connected through the ophthalmic veins with the cavernous sinus.
• Facial vein descends down the face with the facial artery and passes around the lateral side of the mouth.
• Internal jugular vein is where the facial vein drains into.
• Cavernous Sinus Thrombosis results from infections in the orbit, nasal sinuses and superior part of the face.
• Structures that may be affected by the Cavernous Sinus Thrombosis are the following:

  • Cranial Nerves III, IV, and VI
  • Cranial Nerve V (Ophthalmic and Trochlear Division)
  • Internal Carotid Artery
• Facial veins make clinically important connections with the cavernous sinus through the superior ophthalmic veins.
• Dangerous Triangle of the Face

  • Triangular area bounded with an apex opposite the medial angles of the eyes and nose.
  • Also bounded with a base formed by the upper lip.
• Danger Triangle is drained by the Facial Vein and has important communications with the Cavernous sinus.
• Popping a pimple in the "danger triangle" can lead to facial paralysis, brain infection, meningitis, and even death.
• Superficial Temporal Vein - formed on the side of the scalp.
• Superficial Temporal Vein follows the Superficial Temporal Artery as well as the Auriculotemporal Nerve.
• Superficial Temporal Vein

  • Enters the parotid gland
  • Joins the Maxillary Vein to form the Retromandibular Vein.
• Maxillary Vein - formed in the infratemporal fossa from the pterygoid venous plexus.
• Maxillary Vein joins the Superficial Temporal Vein to form the Retromandibular Vein.
• Retromandibular Vein is formed by the union of the Superficial Temporal Vein and Maxillary Vein.

  Retromandibular Vein divides into an anterior and posterior branch once it left the parotid gland.

  • Anterior Branch of RV: joins the facial vein
  • Posterior Branch of RV: joins the posterior auricular vein
• Retromandibular Vein joins the Posterior Auricular Vein to form the External Jugular Vein.
• External Jugular Vein is formed behind the angle of the jaw. It descends across two (2) muscles:

  1. Sternocleidomastoid Muscle
  2. Platysma Muscle
• The External Jugular Vein drains into the Subclavian Vein just behind the middle of the clavicle.
• Anterior Jugular Vein - joins the External Jugular Vein deep to the Sternocleidomastoid Muscle
• Internal Jugular Vein is a large vein that receives blood from the brain, face, and neck.
• Internal Jugular Vein begins in the jugular foramen as a continuation of the Sigmoid Sinus. It descends into the Carotid Sheath then ends in the Brachiocephalic Vein.
• Internal Jugular Vein receives Facial Vein, Lingual Vein, and Superior and Middle Thyroid Veins
• Subclavian Vein is a continuation of the Maxillary Vein at the outer border of the 1st rib. It joins the Internal Jugular Vein to form the Brachiocephalic Vein.
• The Subclavian Vein receives the External Jugular Vein. It often receives the Thoracic Duct and the Right Lymphatic Duct on the right.
• Central Venous Line - an intravenous needle and catheter placed into a large vein such as the Internal Jugular Vein and Subclavian Vein. This is used to give fluids or medication.
• Central Venous Line - also known as Central Venous Catheter

  • Thin, flexible tube
  • One end is put into a large vein (usually in the neck)
  • Other end stays outside the body