<Li> The ethmoidal sinuses, which are formed from several discrete air cells within the ethmoid bone between the nose and the eyes . They are innervated by the ethmoidal nerves, which branch from the nasociliary nerve of the trigeminal nerve . </Li> <Li> The sphenoidal sinuses, in the sphenoid bone . They are innervated by the trigeminal nerve . </Li> <P> The paranasal air sinuses are lined with respiratory epithelium (ciliated pseudostratified columnar epithelium). </P> <P> Paranasal sinuses form developmentally through excavation of bone by air - filled sacs (pneumatic diverticula) from the nasal cavity . This process begins prenatally, and it continues through the course of an organism's lifetime . </P>

Where are the sinuses located and what is their function