Inspiratory reserve volume (IRV)

Definition

Inspiratory Reserve Volume (IRV) is the additional amount of air that can be inhaled after a normal inhalation. It represents the reserve capacity of the lungs for additional ventilation during increased physical activity.

5 Must Know Facts For Your Next Test

1. IRV is measured using spirometry and is an important component of lung function tests.
2. The average IRV for an adult male is approximately 3000 mL, while for an adult female it is around 1900 mL.
3. IRV decreases with conditions such as restrictive lung diseases which limit lung expansion.
4. During vigorous exercise, utilization of IRV allows for greater oxygen intake to meet metabolic demands.
5. IRV, combined with Tidal Volume (TV) and Expiratory Reserve Volume (ERV), contributes to the calculation of Vital Capacity (VC).

Review Questions

• What does Inspiratory Reserve Volume represent in terms of lung function?
• How does Inspiratory Reserve Volume change in individuals with restrictive lung diseases?
• Why is Inspiratory Reserve Volume important during physical activities?

Related terms

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

Expiratory Reserve Volume (ERV): The additional amount of air that can be exhaled after a normal exhalation.

Vital Capacity (VC): The total amount of air that can be exhaled after a maximal inhalation; it includes TV, IRV, and ERV.