North Carolina EMT State Practice Exam

What is the parietal pleura?

1. A membrane covering the lungs

2. A membrane lining the thoracic cavity

3. A type of lung cell

4. A muscle aiding in respiration

The correct answer is: A membrane lining the thoracic cavity

The parietal pleura is correctly identified as the membrane lining the thoracic cavity. This membrane serves an essential function because it provides a protective layer that helps to separate the lungs from the chest wall and other structures within the thoracic cavity. It is composed of a layer of mesothelial cells that produce pleural fluid, which acts as a lubricant, allowing the lungs to expand and contract smoothly during respiration. The distinction between the parietal pleura and the visceral pleura is important; while the visceral pleura covers the lungs themselves, the parietal pleura adheres to the chest wall. This anatomical arrangement helps maintain the negative pressure required for lung inflation and ensures that any movement of the thoracic cavity is transmitted efficiently to the lungs. Understanding this aspect of respiratory anatomy is crucial for EMTs and healthcare professionals as it relates to conditions such as pleurisy or pneumothorax, where the integrity of these membranes can be compromised.