Which structure separates the left and right nasal passages?

The nasal septum is the structure that divides the left and right nasal passages. It is composed of both bone and cartilage, primarily featuring the perpendicular plate of the ethmoid bone and the vomer bone, which serves as its bony foundation, along with the septal cartilage that provides flexibility. This anatomical division plays a crucial role in directing airflow during breathing, contributing to the proper functioning of the respiratory system by ensuring that air moves through each nasal cavity efficiently.

Understanding the structure and function of the nasal septum highlights its significance in maintaining the integrity of the nasal passages and facilitating the warming, humidifying, and filtering processes that occur as air enters the respiratory tract. The nasal conchae, while present within the nasal cavities, assist in the airflow patterns and the conditioning of inhaled air but do not provide the division itself. The choanae refer to the openings at the back of the nasal passages leading into the throat, whereas the vomer bone is a component of the nasal septum rather than the division itself.