Systemic fluid compartments and cell membranes

Systemic fluid compartments and cell membranes represent the physiological spaces and biological barriers that regulate the distribution of water and solutes within the human body. Total body water is partitioned into the intracellular fluid (ICF) and extracellular fluid (ECF), with the latter further divided into interstitial fluid and plasma (StatPearls, 2023). The cell membrane serves as a semi-permeable phospholipid bilayer that maintains these distinct environments through selective permeability and active transport (NIH, 2022). While not a single molecular target, these systems are therapeutically manipulated using osmotic diuretics like mannitol to shift fluid volumes or intravenous fluids to restore hemodynamic stability (Merck Manual, 2023). Furthermore, the lipid bilayer of cell membranes is a site of interaction for certain drugs, such as amphotericin B, which creates pores in fungal membranes, or general anesthetics that historically were thought to act by altering membrane fluidity (PubMed, 2021). Dysregulation of these compartments is a hallmark of various clinical conditions, including edema, dehydration, and congestive heart failure.

Other names

Body fluid compartmentsBiological membranesPlasma membraneIntracellular and extracellular fluidTotal body water compartments

Modulation of osmotic pressure gradients, volume expansion, and physical disruption or stabilization of the lipid bilayer structure.