# Floor of nasal cavity is formed by:
A. Palatine process of maxilla and horizontal part of palatine bone
B. Palatine process of maxilla and vertical part of palatine bone
C. Maxillary process of palatine and horizontal part of maxilla
D. Maxillary process of palatine and vertical part of maxilla
The correct answer is A. Palatine process of maxilla and horizontal part of palatine bone.
The nasal cavities contain:
Respiratory area:
The respiratory area is lined by a pseudostratified , ciliated, columnar epithelium. The epithelium contains goblet cells and a subjacent fibrous lamina propria with mixed mucous and serous glands. The Lateral walls contain conchae, which increase the surface area and promote warming of the inspired air.
Olfactory area:
The olfactory area is located in the posterosuperior nasal cavity and is lined by a pseudostratified epithelium composed of bipolar neurons (olfactory cells), supporting cells, brush cells, and basal cells. The basal cells are stem cells that continuously turn over to replace the olfactory receptor cells. This is the only example in the adult human where neurons are replaced. Under the epithelium, Bowman glands produce serous fluid which dissolves odorous substances.