Originally an extension center of the University of Alabama system, the University of Alabama at Birmingham (UAB) now operates as an independent institution within the system. UAB offers about 140 different baccalaureate, master's, and doctoral degrees, as well as specialist's, first professional, and certificate programs. The university has an enrollment of 18,000 students at a dozen schools, as well as its graduate school. It has a student-teacher ratio of about 17:1. UAB also is home to a health care center and some 80 research centers. Its campus takes up more than 85 city blocks.