Question

A subject has a 450 ml tidal volume and breathes 10 times per minute. What is the alveolar ventilation for this person (ml/min)?

a) 1000

b) 2000

c) 3000

d)4000

Answer 1

Corrct Answer is Option B -2000ml/min

Given that

Tidal volume = 450ml ( it is the volume of air inpired or exhaled during a normal breathing)

respiratory rate = 10/minute ( it is the number of breath taken per minute)

Alveolar ventilation is the volume of gas exchanged between the alveli and the environment in a minute

The equation fo calculating Alveolar ventilation is

Alveolar ventilation = Respiratory Rate * ( Tidal volume - Dead Space )

Where dead space is the volume of air that doesnot takesplace in a gas exchange

Here, the dead space is not specifically given

So, we can take the normal dead space = 150ml

so,

Alveolar ventilation = Respiratory Rate * ( Tidal volume - Dead Space )

= 10 * (450-150) ml /minute

= 10* 200 = 2000ml/minute