Expiratory reserve volume (ERV)

Definition

Expiratory reserve volume (ERV) is the additional amount of air that can be forcibly exhaled after the end of a normal exhalation. It is an important component in assessing lung function and respiratory health.

5 Must Know Facts For Your Next Test

1. ERV is typically measured using spirometry.
2. The average ERV for a healthy adult is approximately 1,200 mL.
3. ERV decreases with conditions such as obesity and restrictive lung diseases.
4. ERV, along with inspiratory reserve volume (IRV), helps calculate vital capacity (VC).
5. Changes in ERV can indicate pulmonary complications or improved respiratory muscle strength.

Review Questions

• What is expiratory reserve volume (ERV) and how is it measured?
• How does obesity affect ERV?
• Why is ERV an important measurement in respiratory health assessments?

Related terms

Tidal Volume (TV): The amount of air inhaled or exhaled during a normal breath.

Inspiratory Reserve Volume (IRV): The additional amount of air that can be inhaled after a normal inhalation.

Vital Capacity (VC): The total volume of air that can be exhaled after maximal inhalation, calculated as TV + IRV + ERV.