Das Venensystem der Extremitäten ist ständigen hydrostatischen Druckveränderungen
ausgesetzt. Es muss neben der Volumenspeicherung auch Funktionen im Stoffaustausch
übernehmen. Die Kenntnis über diese physiologischen Mechanismen hilft im klinischen
Alltag bei der Diagnostik von Venenerkrankungen und bei der Auswahl der Therapieform.
Die Venenfunktion kann durch 4 Grundbausteine definiert werden: Venenanatomie, Herz-Kreislauf-System/Zwerchfellpumpe,
Wadenmuskelpumpe und Fußpumpe.
Abstract
The venous system is constantly subject to changes in hydrostatic pressure in the
extremities as the body changes position. In addition to storing blood volumes, the
venous system also plays an important role in the exchange of substances. In the first
part of the training series, the function of the veins is defined by four basic elements:
vein anatomy, cardiovascular system/diaphragmatic descent, the foot pump, and the
calf muscle pump. Venous valves are duplications of the intima, and valve cycles consist
of an opening, equilibrium, and closing phase. The vascular width of a vein is regulated
by neural-humoral controls so that a sympathetically induced adrenergic stimulation
mediates venous constriction. The calf muscle pump is divided into proximal and distal
parts whose haemodynamic effects differ. In the foot there is a medial and a lateral
plantar vein, with the lateral plantar vein playing a crucial role (foot pump) in
mobilizing blood volume due to its size and venous capacity. The function of the diaphragmatic
descent on the venous return in the supine position without movement of the lower
extremity depends on the degree of filling of the inferior vena cava. In combination
with the calf muscle pump and foot pump, this results in a complex functional unit.
In everyday clinical practice, knowledge of the physiological mechanisms of venous
return helps in the diagnosis of venous diseases, and in the selection of the correct
therapeutic approach.
Schlüsselwörter
Venenphysiologie - Venenklappen - Zwerchfellpumpe - Fußpumpe - Wadenmuskelpumpe -
Kreislaufregulation
Keywords
vein physiology - venous valves - diaphragmatic descent - foot pump - calf muscle
pump - circulatory regulation
