Pleural fluid is essentially a plasma filtrate. It's created as fluid filters from the blood through two membranes.
Understanding Pleural Fluid Composition
Pleural fluid's composition can be understood by considering its origin. The reference provided explains it as:
- A Plasma Filtrate: The base fluid originates from blood plasma.
- Two Membranes Involved:
- Capillary endothelium
- Parietal pleura mesothelium.
These membranes act as filters, allowing some components of plasma to pass through while retaining others. This process resembles sieving, separating components based on size and charge.
Analogy
Think of it like making broth. You start with water (plasma) and put it through a strainer (membranes). The liquid that comes out is broth (pleural fluid), containing some of the ingredients from the original mixture, but not all.
