Final answer:
The nasal conchae, including the superior, middle, and inferior conchae, are curved bony plates that extend horizontally from the lateral walls of the nasal cavity, playing a crucial role in filtering and humidifying incoming air.
Step-by-step explanation:
The structures that extend horizontally along the lateral sides of the nasal cavities are known as the nasal conchae, specifically the superior, middle, and inferior conchae. The superior and middle nasal conchae are part of the ethmoid bone, while the inferior nasal concha is an independent bone. These conchae are thin, curved bony plates that project into the space of the nasal cavity, increasing the surface area for filtering and warming incoming air. Additionally, they enhance the sense of smell and assist in humidifying the air. The superior and middle conchae form part of the lateral walls of the upper nasal cavity. Located in the ethmoid bone, there are also several small, air-filled spaces which are part of the paranasal sinus system.
The ethmoid bone contributes significantly to the structure of the nasal cavity. Not only does it play a part in forming the nasal conchae, but the perpendicular plate of the ethmoid bone also forms the upper portion of the nasal septum, which divides the nasal cavity. This design enables the conchae to disrupt airflow entering the nose, ensuring the air is adequately cleaned and warmed before reaching the respiratory tract.