The invention relates to a catheter for the directional conductance of a body fluid, particularly blood. The catheter includes a line segment which has a film tube defining an inner volume. A first port connects the inner volume to an external volume and a second port, arranged distally from the first port, connects the inner volume with the external volume. During operation of the catheter, the body fluid is conducted in the inner volume directionally between the first and second ports. The line segment includes a reinforcement running in the interior of the film tube. The film tube has a foldable section, a connecting region whereat the film tube is connected to the reinforcement, and a stabilized section having a structured profile.
