This is how I understand it:
Medical Students can borrow $8,500 in subsidized stafford loans a year. They can borrow $38,500 of total stafford loans per year (ie if you were to get the full $8500 subsidized then you could borrow $30,000 of unsubsidized but if you received less subsidized you could receive more unsubsidized). However, you can receive more loans through private loans or other federal loans (ie Perkins) as long as you do not exceed your cost of attendance (this may not be true of private loans but is true for federal loans). There is a lifetime cap on federal debt you can incur (not sure on the amount but I believe it is ~ $160,000) and after that point you would have to seek private loans. Most schools cost more for books, tuition, and fees then you stated. As an instate resident at CU my tuition is ~$16000/year, fees ~ $1000/year, and books ~$1000/year. My cost of attendance (including room and board) is over $30,000 for the first year and $38,500 for every year thereafter (the first year you have the summer off that is why it is less). I hope this clears things up.