Final answer:
The nasal septum is the structure that divides the nose into left and right sections, composed of the septal cartilage, the perpendicular plate of the ethmoid bone, and the vomer bone.
Step-by-step explanation:
The nose is divided into left and right sides by a structure known as the nasal septum. This septum is a flat, midline structure that separates the nasal cavity into two distinct halves. The nasal septum is made up of several parts: the septal cartilage at the front, which is the flexible part you can touch with your fingers; the perpendicular plate of the ethmoid bone, a cranial bone situated just posterior to the nasal bones; and the vomer bone, which is thin and shaped like a plow.
This composition gives a robust framework to the septum and maintains the separation of the nasal passages for proper airflow and function. The nasal septum is formed by the perpendicular plate of the ethmoid bone and the vomer bone, with the septal cartilage filling the gap between these bones and extending into the nose. It separates the nasal cavity into halves.