Sagittal view of the head and nasal septum. The nasal septum is shown intact here and is formed principally by the vomer posteriorly, the perpendicular plate of the ethmoid superiorly, and the septal cartilage anteriorly, all covered by mucosa. In this view, its arterial supply is from the anterior and posterior ethmoidal arteries (branches of the ophthalmic artery), sphenopalatine arteries (branches of maxillary artery), and septal branches of the superior labial artery (not shown). Superior to the nasal septum is the frontal sinus, which drains via its frontonasal duct into the middle meatus on the lateral nasal wall. Posterior to the septum is a view of the sphenoid sinus and the pituitary gland and stalk resting in the sella turcica. Posterior to the dorsum sellae is the basilar artery coursing on the anterior surface of the pons. (Image courtesy of AL Rhoton, Jr.)