On and after July 1, 1973, in every county and city there shall be one court which shall be called the “________________ (Name of County or City) General District Court” and one court which shall be called the “________________ (Name of County or City) Juvenile and Domestic Relations District Court,” and for each such court there shall be one or more judges who shall be called the judge of such general district court or juvenile and domestic relations district court as appropriate. Unless the General Assembly specifically so provides to the contrary, however, no general district court shall be established in any city in which there is no municipal court with general civil or criminal jurisdiction in operation prior to July 1, 1973, and jurisdiction previously exercised in such city by a county court shall be vested in the general district court of such county.