Final answer:
The vomer is an unpaired triangular-shaped bone that forms the posterior-inferior part of the nasal septum. The mandible is an unpaired bone that forms the lower jaw and is the only moveable bone of the skull. Together, these bones are key components of the facial bones that support facial structures and form parts of the cavities for sense organs.
Step-by-step explanation:
The vomer bone is an unpaired facial bone that forms the posterior-inferior part of the nasal septum. It is triangular-shaped and can be seen when looking from behind into the posterior openings of the nasal cavity, forming the entire height of the nasal septum. A smaller portion of the vomer is also visible from the anterior opening of the nasal cavity.
The mandible, another unpaired facial bone, forms the lower jaw and is the only moveable bone of the skull. It starts as paired right and left bones in infancy, which fuse to form the single U-shaped mandible of the adult skull, consisting of a horizontal body and a vertically oriented ramus.
Together, both the vomer and mandible bones, along with the maxilla, palatine, zygomatic, nasal, lacrimal, and inferior nasal conchae bones, and the ethmoid bone, which contributes to the nasal septum and the walls of the nasal cavity and orbit, comprise the facial bones of the skull that support facial structures, form the upper and lower jaws, and provide cavities for the sense organs.