The invention relates to a catheter (10a), comprising a flexible catheter body (10a) forming at least two hollow spaces (90, 100/110) along the longitudinal extension thereof, characterized in that the catheter body (10a) comprises at least two consecutively arranged sections (20) having sheaths (60) that are arranged between the sections (20) and seal the hollow spaces (90, 100/110) at least in some sections, wherein the one hollow space (90) is designed so it communicates with at least one opening (70) penetrating the catheter wall in each section (20), and the other hollow space (100/110) is equipped to introduce an element (40/50) that brings about a longitudinal change of at least one of the sections (20).
