Why are they called Congress(wo)men, and not Representatives?

Hola a todos. Senators are never called Congress(wo)men even though the Senate is the upper body of the US Congress, so why are Representatives called Congress(wo)men? It implies that the Senate is not part of the congress. It’s very sloppy language and I hear it from the corporate media talking heads as well. I also read it from people who don’t know the US system of governance: They don’t know that Senators serve 6 year terms and Representatives serve 2 year terms. I’m sure someone will rush to defend it, but there seems to be a glaring disconnect and that some people don’t seem to understand that anyone in the congress is technically a congresswoman or congressman, not just Representatives from the House of Representatives. If one insists on the sloppy language of Congressman/woman, when might we read Congresswoman Feinstein (the Senator from California) or Congressman Sanders?

Updated: I’m going to start calling everyone in the US Congress “Congress(wo)man” whether they’re in the House or Senate. My way will be more accurate since they are all in the US Congress. Rather than this idiotic practise of only referring to Representatives as “Congress(wo)men.” Chau.—el barrio rosa