Mechanism of Breathing - Respiratory Volumes

Description:

Tidal Volume (TV)

• Volume of air inspired or expired during a normal respiration.
• Approximate tidal volume for a healthy man is 500 mL.
• Healthy man can inspire or expire approximately 6000 to 8000 mL air per minute.

Inspiratory Respiratory Volume (IRV)

• Additional volume of air a person can inspire by a forceful inspiration.
• Appox. 2500 mL to 3000 mL.

Expiratory Reserve  lume (ERV)

• Additional volume of air a person can expire by a forceful expiration.
• Appox. 1000 mL to 1100 mL.

Residual Volume (RV)

• Volume of air remaining in the lungs even after a forceful expiration.
• Average 1100 mL to 1200 mL.

Inspiratory Capacity (IC)

• Total volume of air a person can inspire after normal expiration.
• TV + IRV.

Expiratory Capacity (EC)

• Total volume of air a person can expire after a normal inspiration.
• TV + ERV.

Functional Residual Capacity (FRC)

• Volume of air that will remain in the lungs after normal expiration.
• ERV + RV.

Vital Capacity (VC)

• Maximum volume of air a person can breathe in after a forceful expiration.
• It is also the maximum volume of air a person can breathe out after forced inspiration.
• ERV + TV + IRV.

Total Lung Capacity

• Total volume of air present in the lungs and the respiratory passage at the end of a forced inspiration.
• RV + ERV + TV + IRV or VC + RV.