gewebestrom

Gewebestrom, in physiology, denotes the movement of interstitial fluid and dissolved substances through the extracellular space of tissues. The term is used in German physiology, and in English texts it is often described as interstitial fluid flow. It encompasses the flow of water, ions, nutrients, hormones, and waste products between capillaries, the interstitial space, and lymphatic vessels, enabling cellular supply and waste clearance.

Gewebestrom is governed by Starling forces, including capillary hydrostatic pressure that tends to push fluid into the interstitium and capillary oncotic pressure that draws fluid back into the vascular compartment. The endothelial glycocalyx and interstitial matrix regulate hydraulic conductivity and filtration. Interstitial flow is also driven by tissue metabolism and mechanical forces, and it is modulated by vascular permeability, inflammation, and lymphatic drainage. The lymphatic system returns excess fluid and proteins to the bloodstream, maintaining fluid balance.

Function and importance: supports nutrient delivery, waste removal, immune cell movement, and tissue hydration; influences drug distribution in tissues. Pathological changes in gewebestrom include edema, where excess fluid accumulates, often due to increased capillary permeability, reduced lymphatic drainage, or impaired venous return. In tumors, elevated interstitial pressure can hinder drug penetration and modulate immune cell access.

Measurement and study: researchers use tracer molecules, imaging modalities like MRI or lymphography, and mathematical models to characterize interstitial flow. Understanding gewebestrom informs physiology, pathology, and pharmacology, including tissue engineering and drug delivery design.