The paranasal sinuses are four sets of cavities situated around and connected to the nose. Lined by ciliated columnar epithelium, they help produce mucous (when stimulated by parasympathetic innervation) for the nasal cavity with which they are connected. They also likely function to lighten the skull and act as resonance chambers for speech. Each sinus is innervated by CN V and named by the bone it … Continue reading Paranasal sinuses

The nasal cavity receives blood from three sources: Sphenopalatine and greater palatine arteries, branches of the maxillary artery Anterior and posterior ethmoidal arteries, branches of the ophthalmic artery Superior labial artery, branch of the facial artery CLINICAL CORNER Little’s area is a site of anastomoses between the nasal arteries. Nosebleed commonly occurs here due to drying out and fingernail trauma. Veins follow the course of … Continue reading Nose blood vessels