The nasal cavity is part of which body system's passageways?

• A. Digestive
• B. Respiratory
• C. Nervous
• D. Endocrine

Answer: (B)

The nasal cavity functions as part of the respiratory system’s passageways. It serves as the main entry for air, where it is warmed, humidified, and filtered before moving toward the lungs. Its lining traps dust and microbes, helping condition the air we breathe as it travels from the nostrils to the pharynx, larynx, and beyond. This role aligns with the respiratory system, not the digestive system (which handles processing and absorption of nutrients), the nervous system (which handles signals and processing, though smell does involve nerves, the cavity itself is about air passage), or the endocrine system (which deals with hormones).