[RS] Q.10 What is Pulmonary ventilation, alveolar ventilation, minute respiratory volume ?

Ans.

i)     Pulmonary ventilation:

It means the inflow and out flow of air between the atmosphere and lungs alveoli per minute.

ii)    Alveolar ventilation:

It means the volume of air that enters into the respiratory zone per minute and participates in the gas exchange.

VA   = (VT-VD) Freq.

       = (500-150) × 12      

     = 4200 ml/min.

     = 4.2 L /min.

VA= Alveolar ventilation

VT = Tidal volume= 500ml

VD= Dead space volume (physiological)=150ml

Freq.= Frequency of respiration per minute (respiratory rate)= avg. 12 breaths/min.)

  

iii)   Minute respiratory volume:

It is the total amount of new air moved into the respiratory passages each minute.

Minute res. Volume       = V_T × RR   ( Here, Tidal vol. = 500 ml, Res. rate = 12 breaths/min)

                                      = 500 × 12

                                      = 6000 ml/min.

                                      = 6 Liters/min.