Air volume in lung after normal expiration is called as ?
💡 Explanation
## **Core Concept**
The question tests understanding of lung volumes and capacities, specifically the volume of air remaining in the lungs after a normal, relaxed expiration. This concept is crucial in respiratory physiology.
## **Why the Correct Answer is Right**
The correct answer, **Functional Residual Capacity (FRC)**, is the volume of air present in the lungs at the end of passive expiration. It is the sum of **Residual Volume (RV)**, the volume of air left in the lungs after a maximal expiration, and **Expiratory Reserve Volume (ERV)**, the additional volume of air that can be expired after a normal expiration. FRC is approximately 2400 mL in adults and represents the air left in the lungs when the respiratory muscles are relaxed, and the lungs and chest wall are in equilibrium.
## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and does not provide a choice for evaluation.
- **Option B:** This option is also blank and cannot be assessed.
- **Option C:** Similarly, this option is blank and lacks information for critique.
- **Option D:** This option is blank as well, making it impossible to discuss its inaccuracies.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **Functional Residual Capacity (FRC)** is crucial for maintaining lung volumes and facilitating gas exchange. It is affected by factors such as lung compliance, airway resistance, and the strength of respiratory muscles. Understanding FRC and other lung volumes is essential for diagnosing and managing respiratory diseases.