Respiration bag

A respiration bag having at least one connecting stub, the respiration bag comprising:

• a bag-shaped hollow body defining a longitudinal axis having a direction;
• at least one fold region extending annularly over said body;
• said bag-shaped body being foldable in the direction of said longitudinal axis from a first stable position wherein said hollow body extends smoothly over said fold region to a second stable position wherein said bag-shaped body is bent inwardly in the direction of said axis at said fold region to define an annular fold in said fold region;
• said bag-shaped hollow body has an inner wall surface and a section which remains unchanged in both of said first and second stable positions;
• and,
• said respiration bag further comprises a sealing lip formed along said fold so as to extend essentially parallel to the inner wall surface of said bag-shaped hollow body and said sealing lip has a free edge which extends in the direction of said section when viewed from said fold and moves toward and against said inner wall surface when said bag-shaped body is folded into said second stable position so as to permit inner pressure to act on said sealing lip thereby countering an unintended flip over of the respiration bag back into said first stable position.