Veins of head and neck

• Dura Mater


  Outermost layer of the brain, composed of 2 more layers; venous blood is present between these 2 layers, called dural sinuses

  
• Dura Mater


  • In some areas, the 2 layers are attached to each other
• Dural Venous Sinuses


  • Superior Sagittal Sinus
  • Inferior Sagittal Sinus
  • Transverse Sinus
  • Occipital Sinus
  • Straight Sinus
  • Cavernous Sinus
  • Inferior Petrosal Sinus
• Superior Sagittal Sinus


  Located between periosteal and meningeal layers of dura mater, at the folding between R & L cerebral hemispheres (falx cerebri); starts at Crista Galli, continues along groove for superior sagittal sinus, ends at Internal occipital Crest; drains venous blood to confluence of sinuses, where pathways will then divide to R & L transverse sinuses, sigmoid sinus -> internal jugular vein

  
• Inferior Sagittal Sinus


  Located within the inferior part of the falx cerebri, sitting above the Corpus Callosum; takes venous blood to great cerebral vein, which will then drain blood into the straight sinus

  
• Transverse Sinus


  Located within the horizontal folding of periosteal and meningeal layers of dura, in the internal surface between cerebrum & cerebellum

  
• Occipital Sinus


  Located within falx cerebelli, vertical dural folding

  
• Straight Sinus


  Carries venous blood to the confluence of sinuses; drains blood to the right transverse Sinus

  
• Cavernous Sinus


  Located above sella turcica of sphenoid bone, within diaphragma sellae; another region of dural layers separation; interconnects intracranial veins with extracranial veins; R&L are interconnected by intercavernous sinus; drains blood by superior petrosal sinus into transverse sinus, then sigmoid, then internal jugular vein

  
• Inferior Petrosal Sinus


  Runs anteriorly to the petrous part of temporal bone; venous blood drained from cavernous sinus and can go to 2 more pathways - through sigmoid sinus or directly to int. jugular vein

  
• Supratrochlear vein has functional anastomosis with angular vein

  If venous blood is mainly drained by supratrochlear vein and it is obstructed, angular vein will drain the blood instead
• Facial vein has functional anastomosis with pterygoid plexus by deep facial vein


  If the maxillary vein is obstructed, blood is drained to inferior ophthalmic vein, which then goes to ophthalmic vein, then to cavernous sinus

  
• Drainage of nasal veins

  Angular vein -> lateral nasal -> septal -> superior inferior labial -> facial vein
• Veins draining to Internal Jugular Vein

  • Superior thyroid vein
  • Superficial temporal vein
  • Occipital vein
  • External auricular vein
  • Facial vein
  • Lingual vein
  • Ascending pharyngeal vein

  
• Pterygoid plexus has functional anastomosis with inferior ophthalmic vein
• Pterygoid plexus has no artery equivalent
• Incisor vein


  From incisor teeth and canines, takes venous blood from soft tissues covering the chin
• Inferior alveolar vein


  Passes through mylohyoid canal, carrying dental veins; leaves the mandible by the mandible foramen, collects blood from mylohyoid vein, then goes to pterygoid plexus, which is then drained to maxillary vein
• Inferior labial vein


  Drains blood from lower lip & adjacent parts of the chin
• Superior labial vein


  Drains blood from upper lip & septum