A medical apparatus includes a socket unit for connecting a plug unit of a device for supplying medical fluids, in which the medical apparatus is in particular an extracorporeal blood treatment apparatus, for example an extracorporeal dialysis apparatus or an apparatus for peritoneal dialysis, or an apparatus for filling the device for supplying medical fluids. The socket unit comprises connection pieces for the connection of connectors of a plug unit, so that a flow connection can be produced for supplying or discharging a fluid. The connection pieces are surrounded by connection parts thereby forming rinsing chambers, in which the rinsing chambers are closed by closure pieces, said closure pieces being part of a closure body which is disposed rotatably on the socket unit.