Where does the sphenoid sinus open in the nasal cavity?

The sphenoid sinus opens into the nasal cavity at the superior meatus. This location is significant because it allows for drainage of the sinus directly into the nasal passage, which is crucial for maintaining sinus health and facilitating proper airflow. The superior meatus is positioned beneath the superior nasal concha, and its proximity to the sphenoid sinus makes it the appropriate opening for drainage.

Understanding the anatomy of the nasal cavity and its associated sinuses helps clarify why the superior meatus is the correct site. The other meatuses, such as the inferior and middle meatus, serve different sinuses—the inferior meatus is primarily associated with the nasolacrimal duct, while the middle meatus is where the frontal, maxillary, and anterior ethmoid sinuses drain. The nasal vestibule, on the other hand, is the area just inside the nostrils and does not connect to the sinus cavities, making it an incorrect choice for the location of the sphenoid sinus opening.