Which structure separates the left and right nasal cavities?

The structure that separates the left and right nasal cavities is the vomer. This thin, flat bone forms the posterior portion of the nasal septum, which is the dividing wall between the two nasal passages. The vomer plays a crucial role in supporting the nasal septum, allowing for effective airflow and drainage within the nasal cavities. Its position helps maintain the architectural integrity of the nasal passages, contributing to overall respiratory function.

Understanding the anatomy of the nasal septum is essential, as it not only aids in air passage but also plays a role in filtering, humidifying, and warming the air we breathe. The other options, while relevant structures in the nasal and facial region, do not serve the purpose of dividing the nasal cavities directly.