The main difference between inspiratory reserve volume and expiratory reserve volume is that inspiratory reserve volume is the amount of air a person inhales forcefully after normal tidal volume inspiration, whereas expiratory reserve volume is the amount of air a person exhales forcefully after a normal exhalation.
Inspiratory reserve volume and expiratory reserve volume are two types of lung volumes that change during breathing. Besides, there are two more lung volumes; they are the tidal volume and the maximal expiration.
Key Areas Covered
1. What is Inspiratory Reserve Volume
– Definition, Features, Importance
2. What is Expiratory Reserve Volume
– Definition, Features, Importance
3. Similarities Between Inspiratory Reserve Volume and Expiratory Reserve Volume
– Outline of Common Features
4. Difference Between Inspiratory Reserve Volume and Expiratory Reserve Volume
– Comparison of Key Differences
Key Terms
Expiratory Reserve Volume, Inspiratory Reserve Volume
What is Inspiratory Reserve Volume
Inspiratory reserve volume (IRV) is the amount of air that can be inhaled forcefully after a normal inhalation. Therefore, it is the additional amount of air the lungs take in after inhalation. It occurs during deep breathing. Generally, the inspiratory reserve volume is 3.3 liters in men and 1.9 liters in women. A spirometer is an instrument that measures the airflow that breathes through its mouthpiece. An average person breathes 13 pints of air in a minute. But, inspiratory reserve volume exceeds the tidal volume, which is the amount of air a person inhales and exhales during a normal breath.
Figure 1: Lung Volumes
Furthermore, the average total lung capacity of an adult is about 3 liters of air in adults. Meanwhile, the average human respiratory rate is 12-20 breaths per minute in adults. In addition to that, lung volumes vary from person to person. Generally, taller people have larger lung volumes. People that live at high altitudes and people who are healthy have larger lung volumes. In contrast, some shorter people have smaller lung volumes, while people that live at lower altitudes and that are obese have smaller lung volumes.
What is Expiratory Reserve Volume
Expiratory reserve volume (ERV) is the amount of air that can be exhaled forcefully after a normal exhalation. Therefore, it is the additional amount of air the lungs emit after exhalation. Generally, the expiratory reserve volume is 1.1 liters in men and 0.7 liters in women. However, this volume reduces due to obesity, ascites, and after upper abdominal surgery.
Figure 2: Lung Volumes in Restricted, Normal, and Obstructed Lungs
Moreover, people who spend their lives at high altitudes have larger lung capacity. In comparison, people who spend their lives at sea level have smaller lung capacity. The reason behind that is the partial pressure of oxygen is higher at lower altitudes and lower at higher altitudes. Therefore, at lower altitudes, the oxygen readily diffuses into the bloodstream. Therefore, the diffusing capacity of oxygen increases in order to process more air in higher altitudes.
Similarities Between Inspiratory Reserve Volume and Expiratory Reserve Volume
- Inspiratory reserve volume and expiratory reserve volume are two types of lung volumes that change during breathing.
- Both types of lung volumes can be achieved forcefully.
- Lungs with diseases can change lung volumes.
Difference Between Inspiratory Reserve Volume and Expiratory Reserve Volume
Definition
Inspiratory reserve volume refers to the extra volume of air that can be inspired with maximal effort after reaching the end of a normal, quiet inspiration, while expiratory reserve volume refers to the extra volume of air that can be expired with a maximum effort beyond the level reached at the end of a normal, quiet expiration.
Significance
Usually, inspiratory reserve volume is the amount of air that can be further inhaled after a normal inhalation, while expiratory reserve volume is the amount of air that can be further exhaled after a normal exhalation.
Importance
Inspiratory reserve volume occurs after inhalation, while expiratory reserve volume occurs after exhalation.
Volume
The volume of inspiratory reserve volume is 3.1 liters, while the volume of expiratory reserve volume is 1.2 liters.
Occurrence
Inspiratory reserve volume occurs during deep breathing, while expiratory reserve volume occurs during ascites, obesity, and in upper abdominal surgery.
Conclusion
In brief, inspiratory reserve volume and expiratory reserve volume are two types of lung volumes. Inspiratory reserve volume is the amount of air that can be further inhaled, especially after a normal inhalation. In addition to that, the normal inspiratory reserve volume is 3.1 liters. In comparison, expiratory reserve volume is the amount of air that can be further exhaled, especially after a normal exhalation. Generally, the volume of the expiratory reserve volume is 1.2 liters. Therefore, the main difference between inspiratory reserve volume and expiratory reserve volume is their occurrence.
References:
- “Breathing Capacity.” Biology for Majors II. Lumen.
Image Courtesy:
- “Lungvolumes Updated” By Kapwatt– Own work (CC By-SA 3.0) via Commons Wikimedia
- “Lung volumes in restricted, normal and obstructed lung” By ypothalamus – Own Work (CC BY-SA 3.0) via Commons Wikimedia
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