The inspiratory reserve volume `+` tidal volume `+` expiratory reserve volume is the same as

Options

A. a) inspiratory capacity `+` expiratory reserve volume
B. b) total lung capacity `-` functional residual capacity
C. c) inspiratory capacity `+` functional residual capacity
D. d) inspiratory capacity `+` residual volume.

Explanation

To solve the question, we need to understand the definitions of the different lung volumes involved:

1. **Tidal Volume (TV)**: This is the amount of air that is inhaled or exhaled during normal breathing.

2. **Inspiratory Reserve Volume (IRV)**: This is the maximum amount of air that can be inhaled after a normal inhalation.

3. **Expiratory Reserve Volume (ERV)**: This is the maximum amount of air that can be exhaled after a normal exhalation.

Now, we can analyze the question step by step:

### Step 1: Identify the volumes involved
We have three volumes:
- Inspiratory Reserve Volume (IRV)
- Tidal Volume (TV)
- Expiratory Reserve Volume (ERV)

### Step 2: Add the volumes together
We need to find the sum of these three volumes:
\[ \text{Inspiratory Reserve Volume} + \text{Tidal Volume} + \text{Expiratory Reserve Volume} \]

### Step 3: Relate the sum to a known lung capacity
The sum of Inspiratory Reserve Volume, Tidal Volume, and Expiratory Reserve Volume is known as the **Vital Capacity (VC)**.
Thus:
\[ \text{IRV} + \text{TV} + \text{ERV} = \text{Vital Capacity (VC)} \]

### Step 4: Conclusion
Therefore, the answer to the question is that the sum of the Inspiratory Reserve Volume, Tidal Volume, and Expiratory Reserve Volume is equal to the **Vital Capacity** of an individual.

### Final Answer
The inspiratory reserve volume + tidal volume + expiratory reserve volume is the same as **Vital Capacity (VC)**.

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