Question

Which one of the following is not true about the human respiratory system?

• A. It maintains acid balance.
• B. It maintains Oxygen and Carbon-dioxide balance
• C. It meets the higher oxygen demands.
• D. There is a direct contact between body cells and the surrounding air.

Answer 1

The correct option is D

There is a direct contact between body cells and the surrounding air.

Oxygen taken in during respiration is not responsible for acid regulation in the body. The pH of the blood and body fluids is determined by the amount of carbon dioxide in the system. Carbon dioxide can combine with water to form weak carbonic acid which is the key aspect of the pH of body fluids.