It has often been reported that epistaxis from the posterior part of the nasal cavity is attributable to the sphenopalatine artery in most cases. However, the descending artery may also be one of its causes. In particular, it is postulated that the major palatine artery which is running within the major palatine foramen is the responsible vessel. In cranial preparations of 21 cadavers the course and histology of major palatine artery were studied.
The major palatine artery bends anteriorly in a sharp angle at 5 to 10 mm above the site where it passes through the palatine bone. At this site the artery is nearest to the mucosa. Like the maxillary artery, the major palatine artery is a muscular type artery. However, the outer membrane becomes thinner at the peripheral side. At that peripheral area there may by bone defect. Therefore, it is estimated that the blood vessel may break relatively easily due to exogenous factors.