Question

IC (Inspiratory capacity) is equal to (a) ERV + TV (b) IRV+TV (c) VC + RV (d) \(\mathrm{ERV}+\mathrm{TV}+\mathrm{IRV}\)

Short answer

The correct answer to the exercise is (b). Inspiratory Capacity (IC) is the sum of Inspiratory Reserve Volume (IRV) and Tidal Volume (TV).

Step-by-step solution

Analyze the Options

Firstly, identify which among the given choices matches the definition of Inspiratory Capacity. It is the sum of Inspiratory Reserve Volume (IRV) and Tidal Volume (TV).

Evaluate the correctness of choice (a)

In choice (a), ERV stands for Expiratory Reserve Volume, and TV is Tidal Volume. As per the definition, IC is not the sum of ERV and TV.

Evaluate the correctness of choice (c)

In option (c), VC and RV are vital capacity and residual volume, respectively. IC is not the sum of VC and RV.

Evaluate the correctness of choice (d)

In option (d), ERV, TV, and IRV stand for Expiratory Reserve Volume, Tidal Volume, and Inspiratory Reserve Volume, respectively. The IC is not a sum of all three volumes.

Key concepts

Inspiratory Capacity

Inspiratory Capacity (IC) is an important concept to grasp within the study of respiratory volumes. It represents the total amount of air that you can inhale after a normal exhalation. In other words, it is the sum of two key breathing volumes: the Inspiratory Reserve Volume (IRV) and the Tidal Volume (TV). This is expressed by the equation:\[ \text{IC} = \text{IRV} + \text{TV} \]This capacity is crucial because it reflects the capability of your lungs to draw in air, which can be vital for various physical activities and overall respiratory health.
Understanding IC can help in assessing lung function and can be an indicator of conditions affecting respiratory efficiency.

Inspiratory Reserve Volume

Inspiratory Reserve Volume (IRV) is the additional volume of air that one can inhale with effort after inhaling a normal tidal volume. Essentially, it measures how much more air you can breathe in after a typical inhale.
This reserve is usually accessed during vigorous exercise or moments when the body requires a rapid intake of more oxygen.

• IRV reflects the flexibility and capacity of your respiratory muscles and lungs.
• It is taller people, non-smokers, and athletes often have a higher IRV.
• An average adult has an IRV in the range of 1900-3300 mL.

Recognizing your IRV is important for understanding the full potential of your breathing under different circumstances.

Tidal Volume

Tidal Volume (TV) is the measure of the amount of air that is inhaled or exhaled during a normal breath when at rest. It's the baseline of our breathing cycle and maintains basic respiratory needs. The average tidal volume for a healthy adult is about 500 mL per breath.

• TV is significant because it reflects how well the lungs are ventilating air during rest.
• It can be affected by factors like lung health, physical condition, and altitude.
• Changes in TV can indicate problems or improvements in respiratory function.

Awareness of TV is essential for diagnosing and understanding conditions such as respiratory illnesses or assessing physical performance.