Blood supply to the nose and sinuses

• the nose and sinuses are supplied by the
  • ethmoid branches of the internal carotid artery
  • facial and internal maxillary branches of the external carotid artery.
• the superior part of the nose receives the anterior and posterior ethmoidal arteries - branches of the ophthalmic artery which itself, is a branch of the internal carotid.
• the rest of the nose and sinuses is supplied by the greater palatine, sphenopalatine, and superior labial arteries, all of which are branches of the maxillary artery which itself, is a branch of the external carotid.
• significantly there is a plexus of vessels on the anterior septum - Little's area or Kiesselbach's plexus - where branches of both the internal and external carotid artery anastamose; this is a frequent site for epistaxis.
• venous drainage of the nose and sinuses is via the ophthalmic and facial veins, and the pterygoid and pharyngeal plexuses. Significantly, drainage is such that infection may spread via the veins to the cavernous sinus.

Reference:

• (1) Kucik CJ, Clenney T. Management of epistaxis. American Family Physician 2005; 71(2): 305-11
• (2) Willems PW, Farb RI, Agid R. Endovascular treatment of epistaxis. AJNR Am J Neuroradiol. 2009;30(9):1637-45