The paranasal sinuses, together with other structures of the upper respiratory tract,
A) are where a small percentage of gas exchange occurs.
B) form part of the respiratory membrane.
C) are involved in filtering, warming, and humidifying incoming air.
D) provide a large area for gas exchange between air and circulating blood.
E) are lined by a delicate simple squamous epithelium.

Question

Quizplus · Accepted Answer

The paranasal sinuses, along with other structures of the upper respiratory tract, are involved in filtering, warming, and humidifying incoming air before it reaches the lower respiratory tract. They do not play a significant role in gas exchange, so options A and D are incorrect. The respiratory membrane is formed by structures in the lower respiratory tract, and the paranasal sinuses are not a part of this membrane, so option B is incorrect. The lining of the paranasal sinuses is not simple squamous epithelium, but rather a mucous membrane containing goblet cells, cilia, and mucus-secreting glands, so option E is also incorrect.

The Paranasal Sinuses, Together with Other Structures of the Upper