Extracellular fluid is composed of the blood plasma within the vascular system and the interstitial fluid bathing cells in a ratio of 3:1.
A small portion is in the transcellular space.
The intravascular fluid is what is contained within the blood vessels (i.e., the plasma volume).
It is the circulating plasma that directly interacts with the interstitial fluid of body organs across the walls of the capillary vessels.
Interstitial fluid is fluid surrounding the cells.
Lymph fluid is included in the interstitial volume.
Interstitial fluid is separated from plasma by capillary endothelia.
Transcellular fluid is part of the ECF. Transcellular fluid is contained within specialized cavities of the body. Examples of TCF include cerebrospinal, pericardial, pleural, peritoneal, synovial, intraocular fluids, sweat, urine and digestive secretions.