What is the normal tidal volume in adults?

Question

Question

This question was previously asked in

KGMU Nursing Officer 2023 Memory-Based Previous Year Paper

Answer 1

Correct Answer: 500 ml

Rationale:

Tidal volume (TV) refers to the amount of air that is inhaled or exhaled during a normal, resting breath without any additional effort.
In adults, the normal tidal volume is approximately 500 ml per breath. This value ensures adequate oxygenation and carbon dioxide removal during quiet breathing.
Tidal volume is a critical parameter for maintaining the body's oxygen and carbon dioxide levels within normal ranges, supporting metabolic processes.

Explanation of Other Options:

300 ml

Rationale: While 300 ml could potentially be a tidal volume in smaller individuals or children, it is below the average for adults. Tidal volume in adults typically falls in the range of 400–600 ml, with 500 ml being the standard reference.

1200 ml

Rationale: 1200 ml is much higher than normal tidal volume. It may represent a deep inhalation (inspiratory reserve volume) or the total lung capacity during forceful breathing, but it is not the typical volume exchanged during quiet breathing.

3600 ml

Rationale: 3600 ml is significantly higher than normal tidal volume. It is closer to the inspiratory capacity (the maximum volume of air that can be inhaled after a normal exhalation), which includes the tidal volume and inspiratory reserve volume.

Conclusion:

The normal tidal volume in adults is approximately 500 ml. This value represents the amount of air moved in and out of the lungs during relaxed breathing. Understanding tidal volume is essential in respiratory physiology and clinical settings, especially when managing ventilators or assessing lung function.