Question

If a person IC is 3500 mL; FRC is 2500 mL; and can maintain 1000mL of air in the lungs at all times (RV). Then his vital capacity is 1) 6000 mL 2) 5000 mL 3) 4000 mL 4) 7000 mL​

Answer 1

Answer:

7000 mL​

Explanation:

Residual volume (RV) is the volume of air still remaining in the lungs after the most forcible expiration possible. This accounts for 1100-1200 ml.  

The inspiratory reserve volume (IRV) is the additional amount of air that can be inhaled after a normal inhalation. This is the amount of air which can be taken in by forced inhalation. This accounts for 2500-3000 ml.  

Vital capacity (VC) is the maximum amount of air a person can expel from the lungs after a maximum inhalation. This accounts for 4000-4600 ml.  

The expiratory reserve volume (ERV) is the additional amount of air that can be exhaled after a normal exhalation. This accounts for 1000-1100 ml.  

Inspiratory Capacity (IC) is the maximum amount of air that can be inspired. The amount of air for IC is about 3000-3500 ml.

Answer 2

Answer is 2) 5000ml

Explanation:

• Vital capacity= Tidal volume(TV)+ Inspiratory reserve volume(IRV)+ Expiratory reserve volume(ERV)
• Inspiratory capacity( IC)= TV+IRV=3500ml
• Functional residual capacity(FRC)= Expiratory reserve volume(ERV)+ Residual volume
• so, ERV= FRC - RV=2500 - 1000=1500 ml
• so, Vital capacity is (TV+IRV)+ERV=3500+1500=5000ml