The pleura is a connective tissue sheath that covers which of the following organs?
A.
Liver
B.
Heart.
C.
Spleen
D.
Lung
The Correct Answer and Explanation is:
The correct answer is D. Lung.
The pleura is a double-layered membrane that surrounds the lungs, consisting of two parts: the visceral pleura and the parietal pleura. The visceral pleura directly adheres to the surface of the lungs, while the parietal pleura lines the thoracic cavity. The space between these two layers is known as the pleural cavity, which contains pleural fluid. This fluid serves several critical functions, including lubrication during respiration and maintaining surface tension to prevent the lungs from collapsing.
The primary function of the pleura is to facilitate smooth movement of the lungs as they expand and contract during breathing. As the diaphragm and intercostal muscles contract, the thoracic cavity enlarges, creating a negative pressure that allows air to flow into the lungs. The pleural fluid reduces friction between the pleural layers, enabling efficient respiratory mechanics. Additionally, the pleura plays a role in protecting the lungs from infection and trauma by serving as a barrier.
Understanding the pleura is essential in various medical fields, particularly pulmonology and thoracic surgery. Conditions such as pleuritis (inflammation of the pleura) and pleural effusion (accumulation of fluid in the pleural space) can significantly impact respiratory function. In pleuritis, the friction between the pleural layers can cause sharp pain during breathing. In cases of pleural effusion, the accumulation of fluid can restrict lung expansion, leading to symptoms like shortness of breath.
In summary, the pleura is a crucial connective tissue sheath that envelops the lungs, allowing for efficient breathing mechanics and providing protection against injury and infection. Its role in respiratory health underscores its importance in clinical assessments and interventions related to pulmonary function.