Anatomy of the Nasal Cavity

The nasal cavity consists of two chambers separated by the nasal septum. Its functions include resonating voice, housing the olfactory organ, and filtering, warming, and moistening inhaled air as part of the respiratory tract.

The nasal septum has a mucous membrane with blood vessels for warming air and nutrient supply. The Hasselbach's area is prone to nosebleeds and the sensory innervation is supplied by the trigeminal nerve.

The nasal septum's skeleton consists of bone (ethmoid, vomer, palatine bone, maxilla) and cartilage (septal, vomarine, and alar). Cartilage provides flexibility to the nose.

The lateral wall has superior, middle, and inferior conchae which increase surface area to warm and moisten inhaled air. Spaces around the conchae are called meatuses.

Olfactory receptors are in the olfactory epithelium. The frontal, ethmoidal, sphenoidal, and maxillary sinuses connect to the nasal cavity.

The frontal sinus drains into the hiatus semilunaris. Ethmoidal air cells drain into the middle and superior meatus. Sphenoidal sinus drains into the sphenoethmoidal recess. Maxillary sinus drains into the middle meatus. The nasolacrimal duct drains tears into the inferior meatus.

Sensory innervation of the lateral wall comes from the anterior ethmoidal and maxillary nerves. The ethmoid, palatine bone, and maxilla form the lateral wall. Nasal bone and cartilages form the anterior part.

The nasal cavity filters, warms, and moistens inhaled air using a large surface area created by the septum, conchae, sinuses and narrow passageways.