The part of inhaled gas that undergo exchange in respiratory bronchioles and alveoli is :
A- Tidal Volume
B- Effect Tidal Volume
C- Minute Ventilation
D- Alveolar Ventilation
The correct answer and explanation is:
The correct answer is D- Alveolar Ventilation.
Alveolar ventilation refers to the volume of fresh air that reaches the alveoli (the tiny air sacs in the lungs) and participates in gas exchange. This process is crucial for oxygenation of blood and removal of carbon dioxide from the body.
Here’s how it works: Air enters the lungs through the bronchial tree and reaches the alveoli. However, not all the air that is inhaled is involved in gas exchange. Some air fills the anatomical dead space (the parts of the respiratory tract such as the trachea and bronchi that do not participate in gas exchange). The air that reaches the alveoli, where oxygen and carbon dioxide are exchanged between the lungs and the blood, is what we refer to as alveolar ventilation.
Alveolar ventilation is different from tidal volume, which is the total volume of air that moves in and out of the lungs with each breath, whether it reaches the alveoli or not. Tidal volume includes both the air that goes into the alveoli and the air that fills the anatomical dead space, which does not participate in gas exchange.
Minute ventilation is the total volume of air breathed in and out in one minute, which is a combination of tidal volume and the breathing rate. However, not all of this air contributes to gas exchange, as some of it is in the dead space.
Therefore, alveolar ventilation is the most accurate measure of the volume of air that actually takes part in gas exchange, ensuring the efficient exchange of oxygen and carbon dioxide in the lungs.