Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Total Lung Capacity (TLC) is the maximum volume of air that the lungs can hold after a full inhalation. It includes all the lung volumes: tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume.
5 Must Know Facts For Your Next Test
TLC is typically around 6 liters in an average adult male.
It cannot be measured directly using spirometry because it includes residual volume.
TLC is important for understanding lung health and diagnosing respiratory conditions.
Conditions like emphysema can increase TLC due to air trapping in alveoli.
Restrictive lung diseases, such as pulmonary fibrosis, decrease TLC by reducing lung expansion.
Review Questions
Related terms
Tidal Volume (TV): The amount of air inhaled or exhaled during a normal breath.
Residual Volume (RV): The amount of air remaining in the lungs after a forceful exhalation.
Inspiratory Reserve Volume (IRV): The additional air that can be inhaled after a normal inhalation.