The lesser palatine canals (also accessory palatine canals) are passages in the palatine bone

Palatine bone

The palatine bone is a bone in many species of the animal kingdom, commonly termed the palatum .-Human anatomy:...

 that carry the lesser and middle palatine nerves and vessels.

Structure

The lesser palatine canals start from the greater palatine canal

Greater palatine canal

The greater palatine canal is a passage in the skull that transmits the greater palatine artery, vein, and nerve between the pterygopalatine fossa and the oral cavity.-Structure:...

, and run with them, also opening into the roof of the oral cavity. Their openings are known as the lesser palatine foramina

Lesser palatine foramina

Behind the greater palatine foramen is the pyramidal process of the palatine bone, perforated by one or more lesser palatine foramina which carry the lesser palatine nerve, and marked by the commencement of a transverse ridge, for the attachment of the tendinous expansion of the Tensor veli palatini....

, and they transmit the lesser palatine artery, vein, and nerve, as wll as the middle palatine vessels and nerve.