Why is terminology spoken in doctors offices instead of American english or slang and what would happen?

I am currently attending an online school for Medical Billing and Coding and I wanted to know why the need by doctors, and other medical health care professionals have to speak medical language or terminology. What would hapened if it were put in plain old American english, slang and even ebonics(lol) Is this just a control issue or is it the medical community's way or need(EGO) of wanting to feel superior than the rest of us pions. I'm slow so please keep it real(ghetto term) and direct.