Final answer:
The nasal septum ends inferiorly at the nasal spine. It is comprised of the ethmoid bone and the vomer bone, but the nasal spine, not the inferior nasal concha, marks its endpoint.
Step-by-step explanation:
The nasal septum ends inferiorly at another radiopaque landmark known as the nasal spine. Within the nasal cavity, the septum is comprised of the perpendicular plate of the ethmoid bone and the vomer bone. The inferior nasal concha is an independent bone located laterally in the nasal cavity, and although it is significant in the structure of the nasal cavity, it is not the terminus of the nasal septum. The nasal spine of the maxillary bone is the correct landmark where the inferior portion of the nasal septum ends.