The university originally opened its medical school in 1843, providing instruction in medicine and medical sciences. In 1853, it suspended the school's teaching program and transferred teaching duties to the city's three proprietary schools: Trinity Medical College, the Toronto School of Medicine and Woman's Medical College. Because proprietary schools could not grant degrees, the university's medical school retained the responsibility of holding examinations and conferring medical degrees. As the university kept raising its standards, the medical examinations became increasingly rigorous and scientific. This led to fewer medical students from proprietary schools deciding to obtain university degrees, which were not required for medical practice at the time.