Question

Which of the following is/are correct about the respiratory zone of the human respiratory system?

• A. Alveolar sacs are part of the respiratory zone
• B. The main function is to transport air into the lungs
• C. The respiratory zone is involved in exchange of gases between blood and air
• D. The bronchi and bronchioles are the most important parts of the respiratory zone

Answer 1

Answer: (A), (C)

The correct options are
A Alveolar sacs are part of the respiratory zone
C The respiratory zone is involved in exchange of gases between blood and air

The human respiratory system can be structurally divided into two main zones - the conducting zone and the respiratory zone. The former includes structures that function as a passageway that carries air into and out of the lungs. These structures include the nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles and the terminal bronchioles. The respiratory zone includes structures involved in the exchange of gases between the blood and the air. These include the lungs, respiratory bronchioles, alveolar ducts and alveolar sacs.