I assume from this that you are an international student?
For UK / EU students, there are student loans available to cover fees and living expenses. So yes, 'poor people' can study medicine. However these are not available for international students, and obviously the fees are much higher. I don't know of any scholarships for medicine - and I'm not sure how you would find out except to contact medical schools individually. So to go back to your initial question, the distinction is rather between 'home' students and international students, rather than rich students and poor students. This distinction between 'home' and international needs to be made, as it is expensive to train a doctor, and therefore the fees need to reflect that. Unfortunately consequently it means that it is difficult for international students to study in the UK unless they have the funding - but this is not to discriminate against 'poor people', and UK/EU medical students come from all walks of life and with many varied backgrounds and social / financial situations.