The main difference between alveolar ventilation and pulmonary ventilation is that alveolar ventilation is the gas exchange between alveoli and the external environment whereas pulmonary ventilation is the process of air flowing in the lungs, including inhalation and exhalation.
Alveolar ventilation and pulmonary ventilation are two types of processes that occur in the lungs. They are important for the removal of carbon dioxide while uptaking oxygen into the body.
Key Areas Covered
1. What is Alveolar Ventilation
– Definition, Features, Importance
2. What is Pulmonary Ventilation
– Definition, Features, Importance
3. Similarities – Alveolar Ventilation and Pulmonary Ventilation
– Outline of Common Features
4. Difference Between Alveolar Ventilation and Pulmonary Ventilation
– Comparison of Key Differences
Key Terms
Alveolar Ventilation, Pulmonary Ventilation
What is Alveolar Ventilation
Alveolar ventilation is the exchange of gas between the alveoli and the external environment. It is also responsible for the gas exchange. Oxygen is brought into the lungs from the atmosphere. Carbon dioxide is carried to the lungs through venous blood. Therefore, in the alveoli, carbon dioxide is expelled from the body while entering oxygen into the body. However, alveolar ventilation is defined as the volume of fresh air entering the alveoli per minute. A similar volume of air leaves from the alveoli with carbon dioxide into the outside environment.
Figure 1: Alveolar Circulation
Furthermore, oxygenation is the physiological process that adds oxygen to the body system, occurring in the lungs. The alveoli of the lungs are surrounded by a network of blood capillaries. During inhalation, alveoli are filled with fresh air. Therefore, the red blood cells in the blood capillaries take up oxygen from the air. Basically, this occurs through simple diffusion. The partial pressure of oxygen is high in the air, while the pressure is low in the blood. Thus, oxygen from the air diffuses into the blood.
The main importance of oxygenation is that it increases the partial pressure of oxygen. Red blood cells also transport this oxygen into the tissues. Again, the partial pressure of oxygen in the tissues is low, but the partial pressure is high in the blood. Therefore, oxygen diffuses from the blood into the tissues. Ultimately, this oxygen serves as the final electron acceptor of oxidative phosphorylation in cellular respiration.
What is Pulmonary Ventilation
Pulmonary ventilation is the exchange of air between the lungs and the atmosphere. Generally, it occurs through inhalation and exhalation of the lungs. Here, inhalation is taking air into the lungs, while exhalation is liberating air from the lungs. Moreover, the conducting zones include the nose, pharynx, larynx, trachea, primary bronchi, bronchial tree, and terminal bronchioles.
The main importance of pulmonary ventilation is that it reduces the partial pressure of carbon dioxide in the blood. It mainly occurs through exhalation. Basically, the partial pressure of carbon dioxide is high in the blood in the capillaries, which draw blood into the lungs. However, the partial pressure of carbon dioxide is low in the air. Therefore, carbon dioxide diffuses from the blood to the air. On the other hand, inhalation facilitates oxygenation.
Figure 2: Pulmonary Circulation
Lung volumes and lung capacity measurements are important in measuring pulmonary ventilation. There are four standard lung volumes: inspiratory reserve volume (IRV), tidal volume (VT), expiratory reserve volume (ERV), and residual volume (RV). In addition, there are four standard lung capacities: total lung capacity (TLC), Inspiratory capacity (IC), functional residual capacity (FRC), and vital capacity (VC).
Similarities Between Alveolar Ventilation and Pulmonary Ventilation
- Alveolar ventilation and pulmonary ventilation are two types of ventilation that occur in the lungs.
- They are important for the removal of carbon dioxide from the body while uptaking oxygen into the body.
Difference Between Alveolar Ventilation and Pulmonary Ventilation
Definition
Alveolar ventilation refers to the exchange of gas between the alveoli and the external environment while pulmonary ventilation refers to the process of air flowing into the lungs during inspiration (inhalation) and out of the lungs during expiration (exhalation).
Occurrence
Alveolar ventilation occurs in the alveoli, while pulmonary ventilation occurs in the lungs.
Importance
Moreover, alveolar ventilation is responsible for the removal of carbon dioxide and uptaking oxygen, while pulmonary ventilation is responsible for exhalation and inhalation.
Dead Space
Alveolar ventilation does not depend on the dead space, whereas pulmonary ventilation depends on the dead space.
Conclusion
In brief, alveolar ventilation and pulmonary ventilation are two types of ventilation occurring in the lungs. Both are responsible for the removal of carbon dioxide while uptaking oxygen. Alveolar ventilation is the type of ventilation occurring in the alveoli that is responsible for gas exchange. It does not depend on the dead space of the lungs. In comparison, pulmonary ventilation is the type of ventilation occurring in the lungs. It is responsible for the inhalation and exhalation of air. However, it depends on the dead space of the lungs. Therefore, the main difference between alveolar ventilation and pulmonary ventilation is their importance.
References:
- Chapter 3. alveolar ventilation. AccessMedicine.
- Alveolar Ventilation. Courses Respiratory Mgl2.
Image Courtesy:
- “Alveoli” By helix84 – Own work (CC-BY 2.5) via Commons Wikimedia
- “2317 Spirometry and Respiratory Volumes” By OpenStax College – Own Work (CC BY 3.0) via Commons Wikimedia
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