Medical fluid cassette and medical hose set with a medical fluid cassette

A medical fluid cassette, comprising

• a housing body, which forms a first wall section of a chamber for receiving and/or carrying a medical fluid,
• a cover, which forms a second wall section of the chamber and has a flexible film in at least some sections or is a flexible film in at least some sections,
• a fluid-impermeable insert with a first peripheral section and a second peripheral section, wherein the insert is designed for at least partially filling a cross section of the chamber, wherein the cross section of the chamber is bordered at least by the first wall section and the second wall section, and wherein the insert subdivides the chamber into a first chamber section bordered by the first and second wall sections and a second chamber section bordered by the first and second wall sections, and wherein the fluid-impermeable insert contacts the first and second chamber sections and has at least one opening structure for fluid-permeable connection of the first chamber section to the second chamber section, and
• a receptacle in and/or on the first wall section, wherein the first peripheral section is accommodated in fluid-tight connection with the receptacle.