Final answer:
Pulmonary edema is excess fluid in the air sacs of the lungs, specifically in the interstitial fluid. This fluid belongs to the extracellular fluid (ECF) compartment, which includes various fluids such as blood plasma, cerebrospinal fluid, lymph, and pleural fluid.
Step-by-step explanation:
Pulmonary edema is excess fluid in the air sacs of the lungs, which is most commonly caused by heart and/or kidney failure. The fluid in pulmonary edema is found in the interstitial fluid within the lungs. Interstitial fluid is part of the extracellular fluid (ECF) compartment, which also includes other fluids such as blood plasma, cerebrospinal fluid, lymph, and pleural fluid. Pleural fluid is the fluid found in the pleural cavities surrounding the lungs.