I am studying medicen so I can help out in a hospital
Me too! I work at many hospitals and a whole range of departments such as E.R., My job is tough. 
What other departments are in a hospital. They seem so big.
There is usually a main emergency department thats usually found int he main side of a hospital or other primary care center. Most of the rooms and patient area is further in the back. 
I see. I have also heard there are hospitals just for woman and children?
Yes such as St Judes which is just for children, Ive visited many of them in my days. I'm not too sure about wemon only hospitals though. 
I understand now. When did the first hospitals become a thing?
Well Specialised hospitals didnt become a thing until the early 1800's. Most people back then could not afford health care costs compared to the hospitals we have today.