Which part of the respiratory system contains cilia and olfactory receptors?

The nasal cavity is the correct choice as it contains both cilia and olfactory receptors. The cilia are tiny hair-like structures lining the nasal cavity that help in filtering out dust, pathogens, and other particles from the inhaled air, providing a first line of defense for the respiratory system. These cilia also aid in moving mucus, which traps debris, towards the throat where it can be swallowed or expelled.

In addition to this defensive role, the nasal cavity houses olfactory receptors, which are specialized sensory neurons responsible for the sense of smell. These receptors are located in the olfactory epithelium, a specialized tissue within the nasal cavity that detects airborne chemicals and relays the information to the brain, allowing for the perception of different odors.

While other parts of the respiratory system like the pharynx, trachea, and larynx have their distinct functions, they do not possess both cilia and olfactory receptors in the same way that the nasal cavity does. The pharynx primarily acts as a passageway for air and food, the trachea serves as the windpipe that directs air towards the lungs, and the larynx is primarily involved in voice production and protecting the airway during swallowing. Thus, the