Question

The greatest quantity of air that can be expired after a maximum inspiratory effort is its.
(a)Residual volume
(b)Tidal volume
(c)Vital capacity
(d)Lung capacity

Answer 1

Hint: Lung volumes are also known as respiratory volumes. It refers to the volume of gas in the lungs at a given time during the respiratory cycle. Lung capacities are derived from a summation of different lung volumes.

Complete answer:
- The greatest quantity of air that can be expired after a maximum inspiration is known as Vital capacity.
-Tidal Volume(TV) is the amount of air during one respiratory cycle that can be inhaled or exhaled. The functions of the respiratory centers, the respiratory muscles, and the lung and chest wall mechanics are depicted through tidal volume.
-The usual adult value is 10% of the vital capacity (VC), approximately 300-500 ml (6-8 ml/kg)[3]; but up to 50% of the VC can be increased during exercise.

Additional Information: -Inspiratory Reserve Volume(IRV) is the amount of air that can be forcibly inhaled.
-IRV is normally kept in reserve but is used during deep breathing. 1900-3300ml is the standard adult value.
-Expiratory Reserve Volume(ERV) is the volume of air that can be exhaled forcefully after exhalation of usual tidal volume. 700-1200ml is the usual adult value.
-Residual Volume(RV) is the volume of air that remains after complete exhalation in the lungs. The typical adult value is 1200ml(20-25 ml / kg) on average.
-The total volume of air exhaled after complete inhalation is the Vital Power (VC). The value is around 4800mL, and depending on age and body size, it varies.
-It is determined by summing tidal volume, the volume of the inspiratory reserve, and the volume of the expiratory reserve.
-VC implies the capacity to breathe deeply and cough, indicating the power of inspiratory and expiratory muscle.
-In obstructive disorders, VC is often minimized and often in restrictive disorders.
So, the correct answer is ‘Vital capacity’.

Note: -The average total lung capacity of an adult human male is about 6 liters of air.
-Lung volume measurement is an integral part of pulmonary function tests.
-Depending on the depth of respiration, ethnicity, gender, age, body composition, and some respiratory diseases, these volumes tend to differ.