greater palatine canal greater palatine canal the greater palatine canal (or pterygopalatine canal) is a passage in the skull that transmits the descending palatine artery, vein, and greater and lesser palatine nerves between the pterygopalatine fossa and the oral cavity. greater palatine canalleft palatine bone. posterior aspect. enlarged. (pterygopalatine canal labeled at center left.)left maxillary sinus opened from the exterior. (label "probe in pterygopalatine canal" at center right.)detailsidentifierslatincanalis palatinus majorta98a02.1.00.057ta2462fma57761anatomical terminology structure the greater palatine canal starts on the inferior aspect of the pterygopalatine fossa. it goes through the maxilla and palatine bones to reach the palate, ending at the greater palatine foramen. from this canal, accessory canals branch off; these are known as the lesser palatine canals. the canal is formed by a vertical groove on the posterior part of the maxillary surface of the palatine bone; it is converted into a canal by articulation with the maxilla. the canal transmits the descending palatine vessels, the greater palatine nerve, and the lesser palatine nerve.