The present invention relates to a chamber for a blood treatment system with at least one space defined by a chamber wall and with at least one blood inlet and with at least one inlet for a further fluid, which are connected with the space, wherein both the at least one blood inlet and the at least one inlet for the further fluid are formed on tube sections which protrude into the space of the chamber, wherein in the operating condition of the chamber the space of the chamber is at least partly filled with blood or with a mixture of blood and the further fluid or some other fluid and wherein at least one, preferably both or a plurality of the tube sections have a length such that the blood inlet and/or the inlet for the further fluid are located below the blood or fluid level in the chamber.
