The posterior septal artery is a branch of the sphenopalatine artery.^[1] The posterior septal artery supplies blood to the respiratory region of the nasal septum, which consists of the lower two-thirds of the nasal septum and most of the nasal floor.^[1] The path of the posterior septal artery can be understood by splitting it into three different segments: the pterygopalatine segment, the sphenoidal segment, and the septal segment. ^[1]

In most cases, the posterior septal artery divides from the sphenopalatine artery in the pterygopalatine fossa.^[2] This part of the posterior septal artery is called the pterygopalatine segment.^[1] The posterior septal artery passes through the sphenopalatine foramen to enter the nasal cavity.^[2] To enter the posterior border of the nasal septum, the posterior septal artery travels along the anterior wall of the sphenoid sinus passing by the sphenoid ostium and choana. ^[1] This part of the posterior septal artery is called the sphenoidal segment. ^[1] In this segment, the posterior septal artery becomes divided into a superior and inferior branch.^[1] The superior and inferior branches of the posterior septal artery each split into the terminal septal branches that supply blood to the respiratory portion of the nasal septum. ^[1] This region of the posterior septal artery is named the septal segment.^[1]

• Posterior septal branches of sphenopalatine artery