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How does the nasal septum divide the nasal cavity?

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Illustration showing different animals and their respiratory organs: a spider with book lungs, a chicken with lungs, a sponge with labeled inflow and outflow pores, a fish with gills, and a caterpillar with spiracles. — Respiratory system Different methods of respiration in animals.

The nasal cavity is divided into left and right canals by the nasal septum, which acts as a thin medial wall.1

This wall is composed of both bony and cartilaginous structures. Specifically, the supporting framework of the septum consists of the ethmoid bone in the upper portion, the vomer below, and the septal cartilage toward the front. The septum is covered by a mucous membrane, which is highly vascular and thick in the lower two-thirds, while the upper portion is covered by a more specialized, less vascular olfactory membrane.12