Figure 1-9. The paranasal sinuses (lateral and anterior aspects).
(2) The nasal cavity is separated from the lingual cavity by the hard and soft
palates and from the cranial cavity by the ethmoid bone. The nasal cavity is held
together by periosteal covering and by perichondrium, which extends over the
c. Turbinate Bones and Sinuses.
(1) The turbinate bones of the nasal structure are arranged one above the
other, separated by grooves (the meatuses). These act as drainage passages of the
accessory sinuses and are known as the sphenoethmoidal recess and the superior,
middle, and inferior meatus, respectively.
(2) The nasal sinuses serve as air spaces and communicate with the nasal
cavity via the meatuses. Anteriorly, on each side of the skull, the frontal sinus, the
anterior ethmoid cells, and the maxillary sinus (antrum of Highmore) drain into the
middle meatus; posteriorly, the ethmoid cells and the sphenoid sinus drain into the
superior meatus and the sphenoethmoidal recess. A passageway for the flow of air is
provided by the irregular air spaces present between these structures. Because of their
shape, the air is forced to flow in thin airwaves.
d. Nerve and Blood Supplies.
(1) The sensory nerve supply of the nasal cavity is derived from the
(2) The nose and sinuses receive their blood supply from branches of the
internal maxillary artery. There are masses of communicating veins below the epithelial