Question

Which of the following statements is incorrect regarding the respiratory system ?

• A. Each terminal bronchiole gives rise to a network of bronchi.
• B. The alveoli are highly vascularised.
• C. The lungs are covered by a double-layered membrane.
• D. The pleural fluid reduces friction on the lung surface.

Answer 1

The correct option is A Each terminal bronchiole gives rise to a network of bronchi.

Bronchi to bronchiole

The bronchi are subdivided into small bronchioles which enter in the lungs and terminate into the small bag-like structure alveoli.
Thus, the first statement is incorrect.



Alveoli

The alveoli are sac-like structues that are highly vascularized.

Blood vessels around the alveoli help in gaseous exchange between the alveoli and the blood.

Covering of lungs

The two membranes that cover the lungs are the outer parietal pleura and inner visceral pleura.
There is a cavity in between them called the pleural cavity, which is filled with pleural fluid.

Function of pleural fluid

The function of pleural fluid is to reduce the friction on the surface of the lungs.
This helps the two membranes to slide over each other without friction during the breathing process.

Final answer
a. Each terminal bronchiole gives rise to a network of bronchi