Question

Distinguish between vital capacity and total lung capacity.

Answer 1

Hint: Vital capacity and total lung capacity are values used to denote volumes of air that can be used for specific functions. The lung capacities are the sum of two or more volumes.

Complete answer:

Vital capacity	Total Lung capacity
The vital capacity (VC) is defined as the maximum amount of air that can be inhaled or exhaled during a respiratory cycle.	The total lung capacity (TLC) is the measured total amount of air that the lung can hold.
It is the sum of the expiratory reserve volume (ERV), tidal volume (TV), and inspiratory reserve volume (IRV).	It is the sum of the residual volume (RV), expiratory reserve volume (ERV), tidal volume (TV), and inspiratory reserve volume (IRV), (ERV + IRV + VT = VC).
It is about 4000 mL in healthy human beings.	It is about 5000 - 6000 mL in healthy human beings.
Formula for VC is Vital capacity (VC) = IRV + ERV + VT.	Formula for TLC is Total lung capacity (TLC) = VC + RV.

Additional Information: - The lung volumes such as tidal volume (TV), expiratory reserve volume (ERV), and inspiratory reserve volume (IRV) can be measured using a spirometer.
-The total amount of air inhaled after the normal expiration is called inspiratory capacity (IC). It can also be defined as the sum of both the inspiratory reserve volume and tidal volume. It can be represented as IC = TV + IRV.
- The tidal volume, expiratory reserve volume, inspiratory reserve volume, and residual volume are the four units of measuring volume in the lungs.

Note: - Different animals exhibit different lung capacities based on their activities and their size. Following this, cheetahs have higher lung capacity compared to humans to provide them more energy for their speed. Elephants have higher lung capacity compared to humans owing to their size.
- The factors determining human lung size are genetics, gender, and height.
- The human lungs can hold a maximum of six liters of air.