External openings of the nose

External openings of the nose

• A. Nasal passage
• B. Mouth
• C. Nostrils
• D. Alveoli

Answer: (C)

Nostrils are the external openings of the nose. They sit on the outside of the face and allow air to enter the nasal cavity, where it’s filtered, warmed, and humidified as it moves inward. The nasal passage refers to the internal airways inside the nose, not the outside openings. The mouth is a separate opening used for breathing and eating, not part of the nose itself. Alveoli are the tiny air sacs in the lungs where gas exchange happens, located far inside the respiratory system.

Nostrils are the external openings of the nose. They sit on the outside of the face and allow air to enter the nasal cavity, where it’s filtered, warmed, and humidified as it moves inward. The nasal passage refers to the internal airways inside the nose, not the outside openings. The mouth is a separate opening used for breathing and eating, not part of the nose itself. Alveoli are the tiny air sacs in the lungs where gas exchange happens, located far inside the respiratory system.