Which of these is not a function of the respiratory system?

to exchange gases with the atmosphere
to ventilate the air spaces
transport RBCs (red blood cells) to the tissues
to protect against environmental hazards

transport RBCs (red blood cells) to the tissues

Explanation:

Respiratory system is a term that describes the biological system in organisms; both in animals and plants. Its main function is to carry out gas exchange in the host body. In other words, it is the organs and other parts of the body, that is responsible for breathing, for example, in human beings, it exchanges oxygen and carbon dioxide.

Some of the main functions of respiratory system includes the following:

1. Exchange of gases with the atmosphere

2. Inhalation and Exhalation

3. External respiration: exchange of gases between lungs and bloodstream

4. Internal respiration; exchange of gases between bloodstream and blood tissue