Final answer:
The nasal septum is formed by the perpendicular plate of the ethmoid bone, vomer bone, and septal cartilage. It divides the nasal cavity into halves.
Step-by-step explanation:
The nasal septum is a flat, midline structure that divides the nasal cavity into halves. It is formed by the perpendicular plate of the ethmoid bone, the vomer bone, and the septal cartilage. The perpendicular plate of the ethmoid bone forms the upper portion of the nasal septum, while the vomer bone forms the lower and posterior parts. The septal cartilage fills the gap between these bones and extends into the nose, separating the right and left nostrils.