During gas exchange in the alveoli, what gas is transferred from the alveoli to the blood?

During gas exchange in the alveoli, oxygen is the gas that is transferred from the alveoli to the blood. The alveoli are tiny air sacs in the lungs where the exchange of gases occurs. When you inhale, fresh air enters the alveoli and has a higher concentration of oxygen compared to the carbon dioxide-rich blood in the capillaries surrounding the alveoli.

Oxygen diffuses across the thin walls of the alveoli and enters the blood because of this concentration gradient. Once in the bloodstream, oxygen binds to hemoglobin in red blood cells, where it is transported to various tissues in the body.

This process of oxygen transfer is essential for cellular respiration, where cells utilize oxygen to produce energy. The other gases mentioned do not play a role in this specific transfer from the alveoli to the blood as oxygen does. Carbon dioxide, for example, is the gas that is expelled from the blood into the alveoli to be exhaled.