Final answer:
The perpendicular plate of the ethmoid bone forms part of the nasal septum.
Step-by-step explanation:
The ethmoid bone forms the upper portion of the nasal septum. Within the nasal cavity, the perpendicular plate of the ethmoid bone separates the left and right sides of the nasal cavity, forming the upper part of the nasal septum. It extends from the roof of the nasal cavity to the floor of the anterior cranial fossa. The ethmoid bone also forms the lateral walls of the upper nasal cavity and contributes to the formation of the superior and middle nasal conchae.